Stellar populations associated with the LMC Papillon Nebula

Abstract

We study the Large Magellanic Cloud Papillon Nebula (N159-5), a conspicuous High Excitation Blob (HEB) lying in the star forming complex N159. Using JHK near-infrared photometry obtained at the ESO VLT with the ISAAC camera, we examine the stellar populations associated with the Papillon, tracing their history using stellar evolution models. Two populations are revealed: one composed of young, massive stars with an age ~ 3 Myr, and a second consisting of older lower mass stars of age spreading between 1 and 10 Gyr. We analyze the properties of those populations and discuss their significance in the context of N159. We also estimate that if the star at the center of the Papillon is single its initial mass is ~ 50 solar masses and it is affected by an extinction Av ~ 7 mag. Comment: Accepted in A&A 11 pages, 10 figures, 12 on-line material pages (= 1 table) Some figures have been replaced by jpeg versions to reduce the overall size

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arXiv:astro-ph/0403626v1 26 Mar 2004
Astronomy & Astrophysics manuscript no. meynadier
(DOI: will be inserted by hand later)
February 2, 2008
Stellar populations associated with the LMC Papillon Nebula⋆
F. Meynadier1, M. Heydari-Malayeri1, L. Deharveng2, V. Charmandaris3,1, Th. Le Bertre1,
M .R. Rosa4,⋆⋆, D. Schaerer5,6, and H. Zinnecker7
1, Observatoire de Paris, 61 Avenue de l’Observatoire, F-75014 Paris, France
2Observatoire de Marseille, 2 Place Le Verrier, F-13248 Marseille Cedex 4, France
3Cornell University, Astronomy Department, 106 Space Sciences Bldg., Ithaca, NY 14853, U.S.A.
4Space Telescope European Coordinating Facility, European Southern Observatory, Karl-Schwarzschild-Strasse-2, D-85748
Garching bei M¨ unchen, Germany
5Observatoire de Gen` eve, 51, Ch. des Maillettes, CH-1290 Sauverny, Switzerland
6Laboratoire d’Astrophysique, UMR 5572, Observatoire Midi-Pyr´ en´ ees, 14, Avenue E. Belin, F-31400 Toulouse, France
7Astrophysikalisches Institut Potsdam, An der Sternwarte 16, D-14482 Potsdam, Germany
Received 16 December 2003 / Accepted 22 March 2004
Abstract. We study the Large Magellanic Cloud Papillon Nebula (N159-5), a conspicuous High Excitation Blob (HEB)
lying in the star forming complex N159. Using JHK near-infrared photometry obtained at the ESO VLT with the ISAAC
camera, we examine the stellar populations associated with the Papillon, tracing their history using stellar evolution models.
Two populations are revealed: one composed of young, massive stars with an age ∼ 3 Myr, and a second consisting of older
lower mass stars of age spreading between 1 and 10 Gyr. We analyze the properties of those populations and discuss their
significance in the context of N159. We also estimate that if the star at the center of the Papillon is single its initial mass is
∼50 M⊙ and it is affected by an extinction AV∼7 mag.
Key words. Stars: early-type – Interstellar Medium: individual objects: N159 (LMC) – Galaxies: Magellanic Clouds
1. Introduction
The compact H regions called High-Excitation Blobs (HEB)
constitute a rare class of ionized nebulae in the Magellanic
Clouds. They are characterized by high excitation, small
size, high density, and large extinction compared to typical
Magellanic Cloud H regions. These objects are tightly linked
to the early stages of massive star formation, when the stars
begin to hatch from their parental molecular clouds. For this
reason their study yields valuable information for a better
understanding of the formation of massive stars.
The N159 complex (Henize 1956) lies south of the famous
starburst site 30 Dor and has attracted special attention overthe
years. Its other designations are MC77 (McGee et al. 1972),
LH105 (Lucke & Hodge 1970), and DEM271 (Davies et al.
1976). Itshows severalsigns ofongoingstar formationactivity,
such as infrared sources, cocoon stars, masers, and is also
Send offprint requests to: Fr´ ed´ eric Meynadier,
Frederic.Meynadier@obspm.fr
⋆Based on observations obtained at the European Southern
Observatory, Paranal, Chile; Program 66.C-0172(A). Table 1 is pub-
lished only in electronic form.
⋆⋆Affiliated to the Space Telescope Division of the European Space
Agency, ESTEC, Noordwijk, Netherlands
associated with the most important concentration of molecular
gas in the LMC (Jones et al. 1986; Brooks & Whiteoak 1997;
Johansson et al. 1998). The molecular emission is in fact due
to three distinct giant molecular clouds, known as N159-East,
N159-West, and N159-South. Molecular lines tracing high
density regions are observed towards N159-W and N159-S
in CS, CN, HCN, and HCO+(Heikkil¨ a et al. 1999), while
13CO and upper-level12CO transitions, and the [C] emission
line were mapped towards the three giant molecular clouds,
including N159-E (Bolatto et al. 2000). The region we are
interested in lies near N159-E.
The Papillon Nebula, also called N159-5, to which the
present study is devoted, is the prototype of the HEB family
(Heydari-Malayeri & Testor 1982), which now possesses
several members, such as N160A1, N160A2, N83B, N11A
in the LMC and N88A and N81 in the SMC. Recent HST
observations have resolved most of these objects and revealed
turbulent media typical of newborn massive star regions
marked by strong stellar winds interacting with the ambient
ionized gas (Heydari-Malayeri et al. 1999c,a,b, 2001b,a,
2002a,b). These observations also showed a large extinction
due to local dust associated with ionized gas. In a number of
cases the exciting sources were uncovered as a small cluster of

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2 Meynadier et al.: LMC N159
Fig.1. JHK color composite image of LMC N159 (Ks = red, H = green, J = blue) centered on N159-5, the Papillon nebula.
North is up and East is left. See Fig.2 for star identifications. The field size is 2′.1 × 2′.2 (32pc × 33pc).
massive stars.
In particular, the WFPC2 HST observations revealed that
the featureless blob N159-5 has in fact the morphology of a
“papillon”, i.e. it is a butterfly-shaped ionized nebula with the
“wings” separated by ∼2′′.3 (0.6 pc) (Heydari-Malayeri et al.
1999b, hereafter paper I). Moreover, two subarcsecond fea-
tures resembling a “smoke ring” and a “globule” were detected
in the wings. The images also showed a large number of
subarcsecond filaments, arcs, ridges, and fronts carved in the

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Meynadier et al.: LMC N1593
Fig.2. Finding chart (H filter) for the stars in Fig.1. The numbersrefer to Table 1. Regions A (N159-5)and B are detailed below.
Fig.3. Composite JHKs image (Ks = red, H = green, J = blue) and the
corresponding finding chart (H band) for region A, the central Papillon (see
Paper I).
Fig.4. Finding chart for region B (H
band).

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4Meynadier et al.: LMC N159
ionized gas by the stellar winds from massive stars in the
N159 complex. However, no bright stars associated with the
core of N159-5 could be identified in the HST images. Could
this be due to the extinction by dust large enough to hide the
exciting stars? Since an AV ≥ 6mag was needed to bring an
O8 star below our HST sensitivity limit, we decided to perform
high resolution near-IR imaging of the region with the ESO
Very Large Telescope in order to address this issue and explore
the properties of the stellar population of N159.
2. Observations and data reduction
The N159 region was observed in service mode with the ESO
Very Large Telescope (VLT). The infrared spectro-imager
ISAAC was used at the Nasmyth B focus of UT1 through
filters J on 7 October and H and Ks on 1st March 2001. The IR
detector (Hawaii Rockwell array) had 1024 × 1024 pixels of
18.5µm each (0′′.148 on the sky), thus providinga field of 2.′52.
A set of individual, 10-second exposures was obtained in
each filter using the dithering method with a random offset of
15′′at most. The number of exposures were 10, 30, and 36 for
the J, H, and Ks bands respectively. The coadded frames have
a spatial resolution of 1′′.08 for J, 0′′.74 for H, and 0′′.63 for Ks.
PSF-fitting photometry was carried out in the J, H, and
Ks filters using the DAOPHOT II/ALLSTAR procedures
(Stetson 1987) under the ESO MIDAS reduction package.
It should be noted that these procedures are well adapted to
the high-precision photometry of globular clusters (i.e. tight
groups of point sources with no background emission), but are
not designed for handling regions with very bright and variable
background such as N159. Some alternatives to address
those limitations have been investigated by Deharveng et al.
(1992), and involve an iterative subtraction of the background
as derived from the approximative photometry obtained at
each step. In order to improve this method, we developed a
software, called DENEB for DE-NEBulized photometry. Our
software enables an interactive modification of the intermedi-
ate photometry files as well as a real time check of the validity
and convergence of those modifications since it displays the
resulting residual background.1
Finally the frames were calibrated using the mean atmo-
spheric extinction coefficients and the color equations supplied
by ESO, and three standard stars for determining the zero
points. The average photometricerrors reported by DAOPHOT
are 0.04, 0.04, and 0.05 mag for the faintest stars in J, H, and
Ks respectively. The relative accuracy is better than 0.01 mag
for J, H, and Ks brighter than 17 mag.
We comparedthe resulting magnitudeswith those provided
by the 2MASS point source catalogue (Cutri et al. 2003a)
using a selection of 36 stars which appeared as single in our
1People interested in the use or development of this tool are invited
to contact Frederic.Meynadier@obspm.fr.
frames and were brighter than 15.0 mag in H. After correction
for filter bandpasses (Carpenter 2001; Cutri et al. 2003b) the
mean differences are m(2MASS)–m(ISAAC)=−0.06, −0.08,
and −0.02 mag in J, H, and Ks respectively. Taking into
account the accuracy of the 2MASS photometry for stars of
H = 15 mag (∼± 0.1 mag r.m.s) and the uncertainties involved
in the filter bandpass corrections, we considered these mean
differences not to be significant.
Our astrometry and image registration was tied to the po-
sitions of the same 2MASS stars since it is known that the
r.m.s uncertainty in the positions of the 2MASS catalogue is
< 0′′.3. The astrometry and the photometry of the stars are
given in Table 1, which is available in electronic form as on-
line material and also at the Centre de Donn´ ees astronomiques
de Strasbourg (via anonymous ftp to cdsarc.u-strasbg.fr or via
http://cdsweb.u-strasbg.fr/Abstract.html).
3. Results
3.1. Morphology
A composite color JHKs image of the observed field is shown
in Fig.1, while the corresponding finding chart is presented in
Fig.2. The stars are identified by a number, according to Table
1. Figs.3 and 4 give details on two densely populated regions,
the central Papillon nebula and a small southern cluster.
The field is fairly rich, with 896 stars detected at a 3σ
level in the H band image (limiting magnitude 20), which
has the best S/N ratio. Among them 605 objects are de-
tected at 3σ on all theses frames. Some particularly bright,
but highly reddened stars do not appear in all three filters
and consequently they were not included in the analysis.
Exception was made for a source labeled as #317.1 which
is not detected in the J band while being relativelybright in Ks.
The image is marked by several dark regions and lanes
indicating strong absorption. The Papillon nebula is situated
near the border of a prominent central absorption lane. The
backgroundis dominatedby ionized gas emission but is locally
obscured by heavy extinction. The southern edge of the field
yields a fan-shaped filament already visible on the HST frames
(Paper I). Our new JHKs imagery provides a deeper overview
of the stellar content of N159. We can easily note that the
small, bright cluster south to the Papillon (area B of Fig.2) is
much more visible in the near IR than in the optical (Paper I).
The two reddest stars of the field are #210 and #317.1. The
first one is located in the lower right quadrant of our images
almost 1 arcmin from N159-5, and the second one near the
edge of the absorption lane.
We also note the presence of a number of “peculiar” ob-
jects having an elongated form and a red color: #343, #517,
and #149. The first one seems also to have a tilted shape. The
probability that they result from a chance alignment of several
faint red stars is very low. Since they are physically too ex-

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Meynadier et al.: LMC N1595
tended to be considered as circumstellar disks of the LMC, it is
more likely that they are simply background galaxies.
3.2. The infrared colors and stellar ages
Fig.5 presents the Ks versus H–Ks diagram for the measured
stars towards N159, while Fig.6 displays the corresponding
color-color J – H versus H–Ks diagram. All sources brighter
than H = 20 mag and also detected in J and Ks are taken into
account. Star #317.1, which is not detected in J, is assigned
an upper limit of 20 in this band. We wish to point several
stars in our sample which display rather unique properties.
The square in Figs.5 and 6, identifies star #371, which is the
central point-like source of the Papillon. The eight triangles
correspond to the brightest components of the small southern
cluster marked as region B on Fig.2.
The color-magnitude and color-color diagrams are inter-
preted by overplotting isochrones from Lejeune & Schaerer
(2001) with Z = 0.008 for a distance modulus of 18.5 mag. As
usual with near-IR observations, it is difficult to discriminate
low-mass old stars from young massive stars, because the
evolutionary tracks are nearly parallel to isochrones, resulting
in a very close location on the color-color diagram for those
two populations. This degeneracy is lifted if the mass is
taken into account: color-magnitude and color-color diagrams
should be “coherent”, in the sense that populations found to
be fitted by a given isochrone in one diagram should be fitted
by the same isochrone, within the same mass interval, in the
second. Uncertainties in the photometry though, as well as
lack of knowledge in the variation of the extinction introduce
limitations to the precise determination of the corresponding
isochrone.
The diagrams show the presence of two stellar populations.
The first one is a young population which appears to be
fitted well with a 3 Myr isochrone. Some of the members
of this population are weakly affected by extinction while
other members have reddened colors. The extinction-free
subset is vertically aligned around H – Ks=0.00 in Fig.5,
and the sample affected by extinction has H – Ks colors
around 0.20 mag. This young population is made up of
massive O type stars, and may also contain a component
of reddened B type stars of ∼15 M⊙ spread around H –
Ks=0.2 mag. Apart from this young population, there is a
second population with generally redder colors, which can
be fitted with much older isochrones of least 1 to 10 Gyr in
age. The bulk of the stars in this population are fainter than
Ks = 17 mag and have a mass of about 1 M⊙, although the
brightest members have evolved into giants. This population
is also affected by a varying amount of extinction. The points
lying to the right of the 1-10 Gyr isochrones are much more
extincted, probably representing the stars situated deeper in
the molecular cloud. As was mentioned earlier, it is not clear
which precise isochrone should be used, because we expect
the extinction to be generally high and locally variable. It is,
however, evident that this second population is significantly
Fig.7. Evolution tracks for several masses, plotted from the
Genevagrid of models (Lejeune & Schaerer2001). Solid lines:
LMC metallicity, Z = 0.008; dashed lines: Galactic metallic-
ity, Z = 0.02. Filled squares represent the positions of O9 type
stars of different luminosity class (Vacca et al. 1996)). Open
circle shows the position of #193 (R149), assuming MV be-
tween −6.8 and −6.6, Tef f between 27500 and 34300 K, and
a bolometric correction between −3.4 and −2.7 (Vacca et al.
1996).
older than the first one, and we can notice the existence of a
considerable spread in age among this population. It should
also be underlined that for the metallicity of the LMC a star
ofinitialmass2.15M⊙evolvesintoa giantinless than∼1Gyr.
The color-magnitude diagram can be used to estimate the
extinction of the stars. Assuming that the triangles represent
young massive stars of age ∼3 Myr, their shift to the right
in Fig.5 is attributed to reddening by dust. An extinction
of AV∼5 mag is sufficient to displace the mean position of
that stellar population. The star #371, detected towards the
Papillon, does not seem to have an IR excess, but is affected
by an extinction of AV∼7 mag. This is consistent with paper I,
which found AV ≥ 6 for this central region on the assumption
that extinction would have to be large enough to hide an
hypothetical O8 exciting star. See Sect. 3.3 for comparison
with the CO map.
3.2.1. Isochrone fitting
The apparent magnitudeof star #193, better known as R149 or
Sk−69◦257,is V = 12.389with B−V =–0.081,U−B=–0.962
mag (Schmidt-Kaler et al. 1999), in agreement with V = 12.49
mag (Dufour & Duval 1975), and corresponds to an absolute
magnitude of MV∼–6.8 to –6.6. For an O9 spectral type
(Walborn 1977; Conti et al. 1986) this is marginally consistent
with luminosity class III, but typical of class I (Vacca et al.
1996). A dwarf classification, as suggested by Conti et al.
(1986), seems therefore excluded. The effective temperature
of O9III–I stars is Teff∼34300–32700 K using Vacca et al.

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6 Meynadier et al.: LMC N159
Fig.5. Color-magnitude, Ks versus H – Ks, diagram for the observed stars towards LMC N159 detected in all three filters.
Three isochrones are shown, 3 Myr (dotted red curve), 1 Gyr (dashed blue), and 10 Gyr (dashed-dotted green), computed for
a metallicity of Z = 0.008 (Lejeune & Schaerer 2001) and a distance modulus of 18.5 mag. The upper and lower mass limits
are indicated for the 1 Gyr isochrone. The reddening track, plotted as an arrow, extends to AV=20 mag. The numbers refer to
the stellar identifications presented in Fig.2. Triangles represent a sample of the stars belonging to region B, while the square
(numbered #371) refers to the central point-like source of the Papillon. Stars brighter than Ks = 18 mag and situated near the 3
Myr isochrone are labelled and shown as empty circles.
(1996)’s calibration or typically between 31.6 and 27500
K for the extreme Ia class based on recent model analysis
taking into account non-LTE line blanketing (Martins et al.
2002; Crowther et al. 2002; Herrero et al. 2002; Markova et al.
2004).Thebolometriccorrection,whichis essentiallyindepen-
dent of line blanketing, is then BC ∼−3.4 to −2.7 (Vacca et al.
1996) translating to luminosities logL/L⊙∼ 5.6–6.0.
Fig.7 presents the Geneva evolutionary tracks calculated
for initial masses 20, 25, 40, and 60 M⊙ and metallicities Z
= 0.008 and 0.02 (Lejeune & Schaerer 2001). We reported the
positionofR149onthisdiagram,usingthevaluescalculatedin
the previous paragraph. It indicates an initial mass of the order
of 40 to 60 M⊙, which corresponds to an age of 3 to 5 Myr
using the initial masses predicted for stars of various ages and
MVbetween –6.8 and –6.6 mag (Fig.8, top). This is consistent
with the age range, 1 to 4 Myr, derived from the observed Ks
magnitude (Fig.8, bottom).
3.2.2. The brightest and reddest stars
Based on the color-magnitude and color-color diagrams
(Figs.5 & 6), stars #588, #290, #499, #404, #365, #77, and
#210 may be high mass main sequence members. These stars
can also be very tight multiple systems more or less affected by
local dust. In particular, #365 and #210 are very red, probably
due to their association with the prominent absorption features
in Fig.1. Furthermore, star #210 presents a near infrared
excess typical of some Galactic OB exciting stars, for example
star #82 ionizing the H region Sh2-88B (Deharveng et al.
2000). It is not easy to estimate the extinction and the mass of
such a star, more especially since the possible presence of a
circumstellar disk alters the colors (Lada & Adams 1992). If
single, this star would be one of the most massive stars of the
region, having a mass of ∼100M⊙ while affected by an AV>
20 mag.

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Meynadier et al.: LMC N1597
Fig.6. Color-color, J – H versus H – Ks, diagram for the observed LMC N159 stars. The isochrone reference, symbols, and the
reddening track are as in Fig.5. The arrow attached to star #317.1 is due to the fact that an upper limit of 20 in the J band has
been assumed for it.
A number of reasons also suggest that some of these stars
may be LMC supergiants. Using a bolometric correction of
+2.7 mag in the K band for supergiant stars (van Loon et al.
1999; Le Bertre et al. 2001) and an extinction of AK∼0.5 or
1.0 mag, we find that the brightest stars of the sample have
an absolute MK and bolometric Mbmagnitudes in the range
–8 to –8.5 and –5.7 to –6.2 respectively. These magnitudes
are consistent with M type supergiants, carbon stars, or fainter
AGB stars in the LMC (van Loon et al. 1999; van Loon 2000).
As for #210, which has a redder color of H – Ks=2.1 mag, it
can qualify as an LMC AGB candidate. Future spectroscopic
observations are needed in order to clarify the nature of these
stars.
A third possibility is that at least some of these stars
actually belong to our Galaxy and happen to be along the
line of sight to the LMC. We can make a rough estimate on
their number by establishing the H–R diagram of 2MASS
sources found in a field separated by a few degrees from the
LMC. It appears that in our field ∼14 sources brighter than
Ks = 15 mag might be foreground stars. Those stars cannot
be compared to models computed for the LMC distance
modulus. Our observations also indicate that there are 45 stars
brighter than Ks = 15, so approximately 30 of them should be
considered as belonging to the LMC. The above-mentioned
bright stars have colors placing them in the low-mass end of
any isochrones between 1 to 10 Gyr (Fig.6) adapted to the
LMC, even though they are among the most luminous sources
in Fig.5 where they are located near the high-mass end of the
same isochrones. This apparent contradiction can be explained
if they are foreground Galactic stars: their location should
be compared to “shifted” isochrones in the color-magnitude
diagram in order to account for their different distance moduli,
while the color-color isochrones would remain unchanged.
3.3. The molecular gas distribution
Johansson et al. (1998) used the ESO SEST (Swedish
European Submillimeter Telescope) to map the CO (1–0)
emission towards N159 with a resolution of 40′′. We per-
formed a bilinear interpolation between each grid point in
order to generate the contours corresponding to the molecular
gas associated with the Papillon region. The result, represent-

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8 Meynadier et al.: LMC N159
Fig.9. An H band image of our field with a contour overlay of the12CO(1–0) intensity of the molecular cloud N159-East from
Johansson et al. (1998). The field size and orientation are the same as in Fig. 1, and the SEST ∼40′′ 12CO(1–0) beam is marked
with a dotted circle.
ing the CO emission peak called N159-East, is overlayed on
the H image and presented in Fig.9.
The constraints on AV established in paper I and in the
present work are in good agreement with Fig.9. Since the
mapping is relatively scarce, the location of the two peaks
cannot be precisely determined but they coincide with the
absorption feature bordering the compact H region. The
present picture is in perfect agreement with previous findings
that the main CO peak is shifted to the east of the bulk of the
giant H region N159 mapped in the radio continuum at 843
GHz (Mills & Turtle 1984; Heydari-Malayeri & Testor 1985;
Israel et al. 1996). Regions A and B are both adjacent to the
molecular peaks, region B being less affected by extinction.
It is conceivable that more massive stars be in the process of
birth towards the CO emission maxima.
In order to estimate the extinction corresponding to
the CO peak the optically thin
Bolatto et al. (2000) observed the N159-W component in
13CO and derived a column density of 1.1×1022cm−2for the
13CO transition is needed.
molecular hydrogen H2, corresponding to a column density
of atomic hydrogen of 2.2×1022cm−2. It is known that
the gas-to-dust ratio NH/E(B − V) in the LMC is several
times larger than the Galactic value (Nandy et al. 1981;
Clayton & Martin 1985; Lequeux 1989). Using the conversion
relation NH/E(B − V)=2×1022atoms cm−2mag−1given
by Lequeux (1989) and R = AV/E(B − V) = 3.1, we find a
visual extinction of AV∼3.5 mag for N159-W. The extinction
for N159-E should be smaller since we know that N159-E
is less dense than N159-W (see below). On the other hand,
Dickey et al. (1994) carried out 21-cm H absorption line
observations against background continuum sources towards
N159 using the Australia Telescope Compact Array (ATCA)
interferometer. Their H cloud 0539–697 can be identified
with the molecular cloud N159-E, based on velocity similarity
(Johansson et al. 1998). The CO cloud has the following
characteristics: V = 238 km s−1, ∆V = 6.0 km s−1, log(LCO) =
4.28 K km s−1pc2, whereas those for the H cloud are: V =
244 km s−1, ∆V = 1.6 km s−1, N(H) = 4.46×1022cm2. This
column density corresponds to a visual extinction of AV∼7
mag while that for N159-W, i.e. N(H) = 9.62×1022cm−2,

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Meynadier et al.: LMC N1599
Fig.8. Expected initial mass (top) and Ks magnitude (bottom)
for stars with MVbetween −6.8 and −6.6 mag as a function of
age. The data is taken from the Geneva grid of models for Z =
0.008 (Lejeune & Schaerer 2001). Shaded areas correspond to
points with MV between –6.8 and –6.6. Top: The mass range
deduced from Fig.7 is represented by two horizontal dotted
line at M = 60M⊙and M = 40M⊙. Bottom: The observed Ks
magnitude is represented by a horizontal dotted line at Ks =
12.63 mag.
indicates a larger extinction of AV∼15 mag. A reason why
H observations yield stronger extinctions is that the higher
spatial resolution of the interferometerpicks up denser clumps,
in contrast to CO observations which are affected by beam
dilution. Moreover, it is quite possible that both techniques
do not exactly sample the same zones. Anyhow, the higher
values are supported by our HST (Paper I) and present ISAAC
observations.
4. Discussion
The population of young massive stars, which was discussed
earlier (Sect. 3.2), is spatially distributed over the whole field,
while a sample of it, represented by triangles in Figs.5 and
6, is grouped in a cluster, marked as region B. This grouping
is expected given the young age of these stars. How can
though one explain the separation between this cluster and
the other massive stars which even if they have similar ages
are at a considerable distances from the cluster, for example
∼70′′(∼18pc) for star #193, one of the most distant? One
explanation could be that massive star formation may have
taken place simultaneously at different parts of the molecular
cloud. At these locations the molecular material has been
fully dissociated and ionized, and we do not observe it now.
Alternatively, massive star formation has occurredin cluster B,
and subsequently a number of the members have been ejected
due to the dynamics of the cluster.
It has been shown that once an embedded cluster forms,
three mass evacuation mechanisms work over different
timescales to disrupt it (Kroupa 2001): a) expulsion of em-
bryonic gas (approximately during the first 0–5 Myr), b) mass
loss from evolving stars (significant after ∼3 Myr), and c)
stellar dynamical evaporation and ejection of stars (all times).
Binary-binary collisions are required to produce high velocity
escapees to occur in low density clusters (Leonard & Duncan
1988, 1990), although simple calculations suggest that such in-
teractions are rather unlikely. Recently Vine & Bonnell (2003)
have studied the dynamics of massive stars in young clusters
containing gas and stars. They have shown that the location of
massive stars outside the core of the cluster does not exclude
their formation in the dense cluster core. The massive stars
could have originated in the core, but escaped from that region
during the gas expulsion phase. Furthermore, the ejection of
the OB stars must have happened during an earlier evolution-
ary stage when the cluster was most probably more compact
than today (Portegies Zwart et al. 1999). Assuming that star
#193 has been kicked out of cluster B, an escape velocity of
∼5.5kms−1has been necessary for it to reach its observed
position after a travel time of 3 Myr. This estimate is a lower
limit due to projection on the sky of a three-dimensional con-
figuration in space. Higher velocities are quite possible since
escapees can leave their birthplace with velocities up to 100
kms−1orevenlarger(Leonard & Duncan1990; Kroupa1995).
We note also that all the candidate massive stars are devoid
of proper nebulosity, in contrast to the Papillon. This fact
suggests that the Papillon is probably the youngest visible
massive star formation event in the whole field. The strength
of the molecular hydrogen emission detected towards the
Papillon confirms its nature as a very young star formation
region (Israel & Koornneef 1988; Kawara et al. 1988). In
fact the observed luminosity of the H2 line v = 1 – 0 S(1)
towards the Papillon is two times larger than that observed
at the Orion source (Kawara et al. 1988). The massive star(s)
powering the Papillon have not had enough time to disrupt
the H region. Moreover, the presence of nebulosity excludes
the possibility for the Papillon of ejection from cluster B. It is
therefore conceivable that the Papillon lies somewhat above or
below the mean plane of N159. We believe that the Papillon is
situated at the side nearer to us since it is visible in the optical.
We estimate that star #371, which lies towards the center of
the Papillon, has a mass of ∼50M⊙, even though based on
our current resolution we cannot exclude the possibility that
the star is multiple. Should other massive stars be embedded
inside that nebula, much better spatial resolution and deeper
exposures are required in order to uncover them. From our
previous HST observations we estimated an exciting star
of type at least O8V, ∼30 M⊙ (Vacca et al. 1996), for the
Papillon using the Hβ flux measurement and assuming that

Page 10

10 Meynadier et al.: LMC N159
the H region is ionization bounded (Paper I). The difference
between the two mass estimates is due to the fact the H
region is density-bounded at least towards us and that the flux
correctionfor extinction is not straightforward.The latter point
is probably the reason why the radio continuum observations,
which are less affected by extinction, yield a higher Lyman
continuumflux. In an earlier work (Heydari-Malayeri & Testor
1985), we used the radio continuum observations at 843 MHz,
obtained with a beam of 43′′×46′′, to derive a flux density of
55 mJy for N159-5, after correcting for contamination by the
surrounding field. A resulting ultraviolet flux of ∼1.2×1049
photons indicates an O7V type star of ∼38 M⊙ (Vacca et al.
1996). Given the uncertainties involved, the stellar mass
estimates based on the H emission from the nebula agree well
with the ∼50 M⊙ derived from photometry using evolutionary
models.
An age of ∼3 Myr was derived for the massive star
population using the evolutionary models and supplementary
data on one of the members. We wish to note though that this
age estimate may not be very accurate due to the degeneracy
of the near IR colors of massive stars. In fact any isochrone
between 1 and 10 Myrs would be consistent with our data. We
favored the 3 Myr isochrone in order to meet the requirements
of star Sk−69◦257.
One can also estimate the number of stars which power the
H region N159 on the basis of radio continuumobservations.
Clarke et al. (1976) measured a radio continuum flux density
of 6.5 Jy at 408 MHz using the Molonglo telescope whose
beam had a width of 2′.6×2′.9. The beamwidth is comparable
with the size of our ISAAC field, and the target coordinates
match the position of the Papillon, while the reported pointing
accuracy is 18′′×5′′. The derived Lyman continuum flux of
1.36×1051photons s−1corresponds to some 40 massive stars
of type O5V with an initial mass of ∼50M⊙(Vacca et al.
1996). Taking a Salpeter-like initial mass function with slope
x = −1.5, we can predict the presence of some 360 stars of
mass about 10M⊙ and 3240 stars of ∼2 M⊙. Where are these
40 O5V stars? It is quite possible that they are among the stars
we imaged but due to the degeneracies in the colors mentioned
earlier they can only be clearly identified if spectroscopic
observations were available. Moreover, some of them may be
embedded in the molecular cloud and some situated outside
our ISAAC field.
The color-mag diagram (Fig.5) also shows the presence of
intermediate mass stars of ∼4–10M⊙ on the main sequence
formed together with high mass stars ∼3 Myr ago. This is in
agreement with more detailed results on the Orion Nebular
Cluster (ONC) based on a large body of data (∼3500 stars
identified within ∼2.5 pc of the Trapezium, among which at
least ∼1600 with photometric and spectroscopic data in the
visible) (Hillenbrand 1997). According to these studies, low-,
intermediate-, and high-mass stars have formed together in the
ONC a few Myr ago (Palla & Stahler 1999). However, this
may not be a universal trend since Herbst & Miller (1982)’s
study of NGC3293 led them to the conclusion that in a
cluster low- and intermediate-mass stars form first, with the
process continuing gradually until the high-mass stars appear.
This result is in agreement with more recent findings on star
formation in LMC clusters and associations. For instance,
in the case of the R136 cluster, situated in the LMC 30
Dor, Massey & Hunter (1998) arrived to the conclusion that
intermediate-mass stars began forming some 6 Myr ago and
continued up to the time when the high-mass stars formed, 1–2
Myr ago.
An interesting question is whether the young (∼3 Myr)
and old (∼1–10 Gy) stellar populations have formed in the
same region of space. Although presently we do not have
the necessary data to address this issue and cannot reach a
firm conclusion, it is quite possible that both populations be
spatially unrelated. The LMC is known to have a considerable
depth, the old population can have formed in a different depth
during much earlier star formation activities. In order to get
some insight about this question, we used the 2MASS data
to probe a bare stellar field devoid of any particular nebular
emission lying near the N159 complex (radius 1′.22, centered
on α = 05h39m00s, δ = −69◦47′30′′). The corresponding HR
diagramshows theabsence ofa young,unreddenedpopulation,
but the presence of an old populationresembling the one found
towards N159. Although this population is relatively smaller
in number with respect to that of N159, since 2MASS is not
as deep as our photometry, the presence of the old population
is certain. The old population seems therefore to be a common
background stellar component towards this part of the LMC.
The presence of low-mass pre-main sequence LMC stars
in the above diagrams seems unlikely, even if those objects
are characterized by large near IR colors, H – K∼1.5 mag
(Lada & Adams 1992; Chabrier et al. 2000). A pre-main
sequence star of ∼1 M⊙ has a luminosity of log (L/L⊙)∼1 on
its birthline, correspondingto an observed visual magnitude of
∼21, which is below our detection limit. An intermediate mass
pre-main sequence star of 5 M⊙ has an effective temperature
of ∼11,000 K and log (L/L⊙)∼3, corresponding to a reddened
16 magnitude star, occupying loci around J – H∼0.5 and H
– K=0.5 mag (Lada & Adams 1992). There is a few number
of sources with such colors in Fig.6, given the color uncer-
tainties at those magnitudes. Therefore, we cannot exclude the
possibility that some of those points represent intermediate
mass PMS stars. As for more massive objects, the concept
of pre-main sequence is not applicable to stars above ∼6 M⊙
since the birthline and the ZAMS unify at those mass levels
(Palla & Stahler 1993).
Comparison between LMC N159 and SMC N81 points
out dramatic differences between the environments of these
two HEBs. The present work shows the Papillon as part
of a rich complex containing a large molecular cloud and
a cluster of young, massive stars, whereas our previous
study of SMC N81, based on ISAAC near IR observations
(Heydari-Malayeri et al. 2003), revealed a solitary star for-
mation event. Moreover, since the two compact H regions
have several comparablecharacteristics, if we assume that they

Page 11

Meynadier et al.: LMC N15911
have gone through a similar formation process, then the HEB
formation can take place in both very dense as well as rather
sparse environments.
Acknowledgements. We are grateful to Dr. L.E.B. Johansson for pro-
viding us with the CO map of the N159 molecular cloud. VC would
like to acknowledge the support of JPL contract 960803. FM wishes
to thank Dr. Eric Mandel for his valuable help concerning the DS9
astronomical data visualization application (Joye & Mandel 2003).
We would like also to thank the referee, Dr. Joao Alves, for useful
advices. Finally, this publication makes use of data products from
the Two Micron All Sky Survey, which is a joint project of the
University of Massachusetts and the Infrared Processing and Analysis
Center/California Institute of Technology, funded by the National
Aeronautics and Space Administration and the National Science
Foundation.
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Meynadier et al.: LMC N159, Online Material p 1
Online Material

Page 13

Meynadier et al.: LMC N159, Online Material p 2
Table 1. Astrometry and photometry of sources, with DAOPHOT errors
ID
3
4
5
6
7
8
9
10
11
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
RA (J2000.0)
05:39:52.52
05:39:52.55
05:39:52.66
05:39:52.71
05:39:52.71
05:39:52.71
05:39:52.77
05:39:52.77
05:39:52.84
05:39:52.89
05:39:52.92
05:39:53.01
05:39:53.05
05:39:53.05
05:39:53.08
05:39:53.11
05:39:53.12
05:39:53.12
05:39:53.16
05:39:53.18
05:39:53.21
05:39:53.20
05:39:53.23
05:39:53.26
05:39:53.31
05:39:53.35
05:39:53.37
05:39:53.39
05:39:53.43
05:39:53.44
05:39:53.52
05:39:53.54
05:39:53.58
05:39:53.57
05:39:53.60
05:39:53.64
05:39:53.65
05:39:53.67
05:39:53.69
05:39:53.69
05:39:53.71
05:39:53.77
05:39:53.80
05:39:53.84
05:39:53.84
05:39:53.87
05:39:53.94
05:39:53.96
05:39:54.01
05:39:54.01
05:39:54.02
05:39:54.03
05:39:54.06
DEC (J2000.0)
-69:45:24.9
-69:45:14.9
-69:44:42.7
-69:44:05.3
-69:45:17.2
-69:45:14.6
-69:44:39.1
-69:45:31.2
-69:45:34.8
-69:44:36.5
-69:45:24.2
-69:45:18.0
-69:43:50.9
-69:45:26.0
-69:45:13.6
-69:44:48.0
-69:45:15.6
-69:45:41.9
-69:45:09.3
-69:44:40.0
-69:43:34.8
-69:45:40.3
-69:44:17.3
-69:45:23.8
-69:43:54.4
-69:44:25.9
-69:45:11.6
-69:44:24.5
-69:44:56.6
-69:44:22.1
-69:44:08.5
-69:44:13.7
-69:43:59.5
-69:44:54.7
-69:45:35.8
-69:43:52.3
-69:45:24.1
-69:44:29.3
-69:43:45.3
-69:43:48.4
-69:45:32.1
-69:43:46.8
-69:45:14.9
-69:43:55.7
-69:45:33.1
-69:44:56.6
-69:44:00.9
-69:43:41.4
-69:44:09.3
-69:44:52.3
-69:45:35.4
-69:45:16.0
-69:44:24.3
J (mag)
18.32
17.54
18.50
16.04
14.22
19.03
17.45
18.90
15.49
19.46
19.04
14.65
17.68
17.31
19.57
18.80
17.36
16.74
18.80
19.65
17.57
15.76
18.14
16.85
17.13
19.31
16.40
18.04
17.53
17.82
17.10
18.45
19.50
18.11
14.55
17.30
19.39
14.39
19.05
18.12
19.30
17.98
19.37
19.86
18.06
17.73
19.44
18.33
18.31
18.17
16.21
19.88
18.79
H (mag)
18.31
17.26
17.83
16.03
14.04
18.65
16.53
18.31
14.71
18.87
17.95
14.36
17.07
16.83
19.02
18.36
17.00
16.03
18.55
18.87
17.28
15.00
17.22
16.16
16.93
18.84
15.86
17.93
16.85
17.38
16.92
17.55
18.74
17.42
14.24
16.69
18.73
13.50
18.22
17.23
18.50
17.77
18.65
19.23
17.62
17.09
18.49
17.97
17.77
17.54
15.46
18.15
18.30
Ks (mag)
18.18
17.17
17.56
15.99
13.93
18.38
16.21
18.14
14.59
18.54
17.67
14.25
17.00
16.79
18.61
18.34
17.00
15.92
18.23
18.46
17.16
14.80
16.95
16.10
16.95
18.76
15.75
17.93
16.79
17.31
16.90
17.32
18.73
17.24
14.11
16.63
18.45
13.33
17.58
17.04
18.29
17.79
18.38
19.04
17.50
17.05
18.19
17.94
17.73
17.25
15.36
17.72
18.27
σJ
0.019
0.009
0.014
0.005
0.004
0.038
0.007
0.017
0.005
0.028
0.023
0.006
0.008
0.007
0.047
0.013
0.014
0.014
0.024
0.042
0.012
0.006
0.008
0.006
0.007
0.021
0.012
0.009
0.010
0.008
0.006
0.015
0.027
0.011
0.003
0.008
0.048
0.004
0.016
0.011
0.034
0.011
0.025
0.031
0.032
0.015
0.022
0.011
0.012
0.011
0.011
0.036
0.015
σH
0.031
0.018
0.011
0.003
0.005
0.040
0.006
0.020
0.008
0.027
0.012
0.005
0.006
0.008
0.063
0.021
0.012
0.007
0.025
0.028
0.010
0.005
0.006
0.005
0.006
0.029
0.025
0.011
0.007
0.007
0.005
0.008
0.024
0.008
0.004
0.004
0.027
0.001
0.016
0.008
0.025
0.010
0.022
0.030
0.012
0.007
0.018
0.011
0.010
0.010
0.004
0.021
0.017
σKs
0.031
0.012
0.011
0.004
0.004
0.041
0.006
0.021
0.011
0.022
0.015
0.006
0.008
0.011
0.043
0.023
0.012
0.011
0.026
0.026
0.012
0.008
0.008
0.007
0.008
0.032
0.039
0.016
0.008
0.009
0.006
0.009
0.031
0.011
0.006
0.006
0.028
0.003
0.012
0.013
0.028
0.013
0.026
0.043
0.011
0.010
0.018
0.014
0.011
0.010
0.007
0.021
0.018
notes
continued...

Page 14

Meynadier et al.: LMC N159, Online Material p 3
Table 1. continued...
ID RA (J2000.0)
57 05:39:54.06
58 05:39:54.08
59 05:39:54.08
6005:39:54.23
61 05:39:54.25
6205:39:54.27
6305:39:54.30
64 05:39:54.35
6505:39:54.36
66 05:39:54.41
67 05:39:54.43
6805:39:54.46
6905:39:54.54
70 05:39:54.56
7105:39:54.72
72 05:39:54.73
73 05:39:54.76
74 05:39:54.89
75 05:39:54.96
76 05:39:55.02
77 05:39:55.05
78 05:39:55.09
79 05:39:55.12
80 05:39:55.13
82 05:39:55.19
83 05:39:55.29
84 05:39:55.31
8505:39:55.32
86 05:39:55.33
87 05:39:55.36
88 05:39:55.37
8905:39:55.41
91 05:39:55.44
9205:39:55.46
93 05:39:55.51
9405:39:55.57
95 05:39:55.58
9605:39:55.63
97 05:39:55.65
9805:39:55.69
9905:39:55.69
10005:39:55.72
10105:39:55.83
10205:39:55.86
103 05:39:55.91
10405:39:55.92
105 05:39:55.95
106 05:39:55.97
10705:39:56.01
10805:39:56.00
10905:39:56.11
11005:39:56.12
11105:39:56.13
11205:39:56.14
11305:39:56.17
DEC (J2000.0)
-69:45:23.2
-69:44:34.0
-69:45:28.0
-69:45:28.8
-69:45:40.6
-69:44:39.1
-69:43:58.6
-69:45:07.2
-69:44:54.5
-69:44:41.3
-69:43:34.0
-69:44:03.0
-69:44:46.9
-69:44:58.0
-69:43:31.1
-69:45:14.4
-69:45:12.7
-69:44:30.3
-69:45:19.0
-69:44:25.8
-69:45:22.2
-69:43:53.5
-69:44:34.2
-69:44:14.5
-69:44:52.6
-69:43:59.3
-69:44:06.4
-69:44:27.0
-69:44:30.2
-69:44:51.0
-69:43:44.0
-69:45:15.7
-69:45:37.4
-69:44:55.3
-69:44:16.0
-69:45:08.7
-69:44:24.5
-69:45:29.7
-69:44:27.8
-69:44:00.9
-69:44:25.7
-69:44:53.6
-69:43:34.9
-69:43:42.3
-69:45:28.9
-69:43:38.7
-69:45:11.8
-69:45:14.6
-69:43:49.4
-69:44:48.8
-69:45:03.2
-69:43:41.1
-69:44:28.5
-69:45:00.4
-69:44:37.7
J (mag)
17.64
18.99
18.41
18.88
15.74
17.42
18.74
17.63
18.73
17.77
17.03
18.48
18.52
19.54
15.75
19.28
18.91
18.75
19.50
14.04
15.27
19.44
19.06
19.28
19.06
19.27
18.22
17.89
18.29
19.79
19.47
19.27
19.83
19.71
15.62
19.03
19.81
16.25
19.65
16.80
19.34
18.99
18.78
18.02
18.48
17.64
17.86
16.08
18.70
19.52
17.18
18.02
16.88
18.74
18.41
H (mag)
17.16
18.47
17.98
18.63
15.20
16.84
18.44
17.16
17.66
17.18
16.43
17.62
17.58
18.70
14.59
18.09
18.51
18.01
18.49
13.92
13.66
18.35
18.62
18.91
18.04
19.34
17.55
16.77
18.13
19.24
18.63
18.10
18.97
18.62
14.58
18.42
19.16
15.52
19.09
16.67
19.21
18.06
17.93
17.26
17.67
17.46
16.53
15.60
18.54
18.87
16.89
17.27
16.12
17.69
17.66
Ks (mag)
17.04
18.28
18.01
18.46
15.17
16.75
18.35
17.10
17.40
17.12
16.19
17.38
17.33
18.50
14.14
17.61
18.20
17.77
18.07
13.91
13.09
18.03
18.44
18.83
17.70
19.12
17.53
16.54
18.12
18.93
18.42
17.61
19.00
18.36
14.28
18.00
19.14
15.23
19.00
16.70
19.05
17.86
17.62
17.13
17.49
17.48
15.86
15.40
18.52
18.74
16.85
17.14
15.95
17.37
17.36
σJ
0.009
0.021
0.014
0.026
0.005
0.006
0.015
0.009
0.016
0.009
0.011
0.013
0.012
0.027
0.033
0.028
0.021
0.014
0.032
0.003
0.005
0.025
0.016
0.024
0.018
0.031
0.011
0.012
0.010
0.029
0.027
0.027
0.036
0.029
0.004
0.023
0.051
0.005
0.031
0.007
0.031
0.019
0.020
0.006
0.019
0.008
0.010
0.005
0.015
0.030
0.007
0.009
0.010
0.019
0.013
σH
0.008
0.018
0.013
0.024
0.006
0.004
0.016
0.009
0.015
0.007
0.004
0.009
0.008
0.026
0.019
0.016
0.019
0.015
0.023
0.001
0.002
0.015
0.021
0.025
0.012
0.048
0.010
0.006
0.013
0.041
0.019
0.017
0.038
0.021
0.002
0.015
0.029
0.003
0.032
0.009
0.034
0.011
0.012
0.007
0.011
0.007
0.004
0.004
0.020
0.022
0.005
0.007
0.015
0.009
0.008
σKs
0.009
0.021
0.021
0.028
0.007
0.005
0.016
0.013
0.009
0.008
0.006
0.009
0.008
0.021
0.016
0.016
0.027
0.014
0.017
0.003
0.004
0.013
0.020
0.029
0.016
0.041
0.010
0.007
0.015
0.032
0.026
0.018
0.046
0.022
0.002
0.019
0.043
0.005
0.032
0.009
0.035
0.015
0.011
0.008
0.015
0.012
0.004
0.005
0.024
0.023
0.009
0.008
0.015
0.010
0.010
notes
continued...

Page 15

Meynadier et al.: LMC N159, Online Material p 4
Table 1. continued...
ID RA (J2000.0)
11405:39:56.26
115 05:39:56.32
116 05:39:56.32
11705:39:56.34
11805:39:56.37
11905:39:56.41
12005:39:56.43
121 05:39:56.46
12205:39:56.48
123 05:39:56.57
124 05:39:56.62
12505:39:56.64
12605:39:56.70
127 05:39:56.73
128 05:39:56.80
129 05:39:56.93
130 05:39:56.95
13105:39:56.95
132 05:39:56.95
133 05:39:57.01
13405:39:57.07
135 05:39:57.10
136 05:39:57.11
13705:39:57.12
138 05:39:57.15
139 05:39:57.16
140 05:39:57.16
14105:39:57.16
142 05:39:57.25
14305:39:57.26
14405:39:57.33
14505:39:57.34
14605:39:57.38
148 05:39:57.53
14905:39:57.66
15005:39:57.68
152 05:39:57.74
15405:39:57.75
15505:39:57.75
15605:39:57.77
15705:39:57.78
15805:39:57.80
16005:39:57.82
16105:39:57.82
16205:39:57.83
16305:39:57.83
164 05:39:57.88
165 05:39:57.88
16605:39:57.92
16705:39:57.96
16805:39:58.04
16905:39:58.06
17005:39:58.08
17105:39:58.13
17205:39:58.16
DEC (J2000.0)
-69:44:48.9
-69:43:50.2
-69:45:03.4
-69:44:38.8
-69:43:52.7
-69:44:47.3
-69:45:26.9
-69:44:53.8
-69:45:11.2
-69:45:14.3
-69:43:56.7
-69:44:19.4
-69:45:03.1
-69:43:52.0
-69:45:31.5
-69:44:17.7
-69:44:49.1
-69:44:01.8
-69:44:57.5
-69:43:56.3
-69:44:07.4
-69:44:38.3
-69:43:53.3
-69:44:45.6
-69:44:05.4
-69:43:35.9
-69:43:45.7
-69:45:32.9
-69:44:56.9
-69:43:33.5
-69:45:35.6
-69:44:48.2
-69:43:46.0
-69:44:13.4
-69:45:30.6
-69:44:50.3
-69:43:37.6
-69:44:21.5
-69:45:10.1
-69:44:15.3
-69:44:55.3
-69:43:31.8
-69:44:12.6
-69:45:03.3
-69:43:47.7
-69:45:33.9
-69:43:45.0
-69:44:44.4
-69:44:26.1
-69:44:08.8
-69:44:54.0
-69:44:38.3
-69:43:54.6
-69:43:35.6
-69:43:49.2
J (mag)
17.83
16.38
17.55
18.68
18.70
18.07
17.10
18.02
19.45
18.57
18.28
18.21
17.45
18.45
19.00
16.76
16.21
19.42
19.20
16.98
19.95
18.56
17.96
15.79
18.23
18.63
16.57
18.17
19.35
18.05
19.24
17.22
16.85
19.17
19.72
17.57
17.64
19.49
19.26
17.77
15.60
19.03
17.44
18.96
14.93
16.34
18.53
16.76
18.60
18.67
15.91
18.59
17.83
17.92
19.59
H (mag)
17.15
15.59
17.23
17.74
18.21
17.21
16.37
17.27
18.19
17.89
17.61
17.46
17.35
18.09
18.46
15.88
15.43
19.17
18.24
16.98
19.51
17.98
17.87
14.75
17.32
18.58
15.85
17.59
18.70
18.24
18.72
16.32
15.97
18.99
18.26
17.29
16.92
19.01
17.88
17.55
15.31
19.17
16.88
17.91
14.10
16.18
17.68
16.54
17.65
17.73
15.19
18.42
17.22
17.37
18.56
Ks (mag)
16.95
15.45
17.17
17.41
18.14
16.96
16.02
17.10
17.81
17.79
17.51
17.22
17.39
18.14
18.14
15.64
15.23
19.16
17.93
16.96
19.08
17.71
17.86
14.44
17.02
18.47
15.67
17.46
18.47
18.14
18.71
16.07
15.77
18.85
17.14
17.20
16.84
18.82
17.00
17.46
15.20
18.98
16.58
17.32
13.98
16.17
17.55
16.40
17.38
17.41
15.02
18.29
17.10
17.27
18.33
σJ
0.009
0.005
0.008
0.018
0.018
0.007
0.007
0.009
0.029
0.016
0.013
0.011
0.009
0.014
0.022
0.007
0.004
0.026
0.017
0.017
0.044
0.015
0.008
0.005
0.009
0.019
0.006
0.012
0.022
0.025
0.024
0.005
0.008
0.026
0.036
0.007
0.008
0.026
0.020
0.007
0.004
0.032
0.008
0.015
0.005
0.006
0.014
0.007
0.015
0.015
0.005
0.016
0.008
0.011
0.032
σH
0.009
0.003
0.007
0.009
0.021
0.008
0.004
0.008
0.017
0.013
0.009
0.007
0.009
0.013
0.024
0.003
0.002
0.029
0.016
0.012
0.042
0.012
0.010
0.002
0.008
0.018
0.003
0.009
0.022
0.019
0.025
0.004
0.004
0.036
0.032
0.006
0.006
0.023
0.010
0.008
0.002
0.034
0.005
0.013
0.002
0.005
0.013
0.014
0.010
0.009
0.003
0.022
0.007
0.008
0.025
σKs
0.010
0.003
0.009
0.009
0.019
0.009
0.005
0.008
0.017
0.017
0.012
0.010
0.013
0.022
0.028
0.002
0.004
0.038
0.017
0.012
0.041
0.011
0.013
0.002
0.008
0.022
0.004
0.010
0.031
0.020
0.037
0.005
0.004
0.037
0.052
0.007
0.007
0.024
0.009
0.009
0.003
0.037
0.005
0.011
0.002
0.009
0.013
0.027
0.017
0.010
0.003
0.023
0.009
0.010
0.030
notes
continued...