J. L. Rosenberg

George Mason University, Fairfax, Virginia, United States

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Publications (72)217.98 Total impact

  • Jason E. Young, Caryl Gronwall, John J. Salzer, Jessica L. Rosenberg
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    ABSTRACT: We examine the UV reprocessing efficiencies of warm dust and polycyclic aromatic hydrocarbons (PAHs) through an analysis of the mid- and far-infrared surface luminosity densities of 85 nearby H$\alpha$-selected star-forming galaxies detected by the volume-limited KPNO International Spectroscopic Survey (KISS). Because H$\alpha$ selection is not biased toward continuum-bright objects, the KISS sample spans a wide range in stellar masses ($10^8$-$10^{12}\rm{M}_\odot$), as well as H$\alpha$ luminosity ($10^{39}$-$10^{43}\rm{ergs/s}$), mid-infrared 8.0$\mu$m luminosity ($10^{41}$-$10^{44}\rm{ergs/s}$), and [Bw-R] color (-.1-2.2). We find that mid-infrared polycyclic aromatic hydrocarbon (PAH) emission in the Spitzer IRAC 8.0$\mu$m band correlates with star formation, and that the efficiency with which galaxies reprocess UV energy into PAH emission depends on metallicity. We also find that the relationship between far-infrared luminosity in the Spitzer MIPS 24$\mu$m band pass and H$\alpha$-measured star-formation rate varies from galaxy to galaxy within our sample; we do not observe a metallicity dependence in this relationship. We use optical colors and established mass-to-light relationships to determine stellar masses for the KISS galaxies; we compare these masses to those of nearby galaxies as a confirmation that the volume-limited nature of KISS avoids strong biases. We also examine the relationship between IRAC 3.6$\mu$m luminosity and galaxy stellar mass, and find a color-dependent correlation between the two.
    07/2014;
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    ABSTRACT: Since the 1980's discovery of the large (2x10^9 Msun) intergalactic cloud known as the Leo Ring, this object has been the center of a lively debate about its origin. Determining the origin of this object is still important as we develop a deeper understanding of the accretion and feedback processes that shape galaxy evolution. We present HST/COS observations of three sightlines near the Ring, two of which penetrate the high column density neutral hydrogen gas visible in 21 cm observations of the object. These observations provide the first direct measurement of the metallicity of the gas in the Ring, an important clue to its origins. Our best estimate of the metallicity of the ring is ~10% Zsun, higher than expected for primordial gas but lower than expected from an interaction. We discuss possible modifications to the interaction and primordial gas scenarios that would be consistent with this metallicity measurement.
    The Astrophysical Journal 06/2014; 790(1). · 6.73 Impact Factor
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    ABSTRACT: We present HI spectral-line imaging of the extremely metal-poor galaxy DDO 68. This system has a nebular oxygen abundance of only 3% Z$_{\odot}$, making it one of the most metal-deficient galaxies known in the local volume. Surprisingly, DDO 68 is a relatively massive and luminous galaxy for its metal content, making it a significant outlier in the mass-metallicity and luminosity-metallicity relationships. The origin of such a low oxygen abundance in DDO 68 presents a challenge for models of the chemical evolution of galaxies. One possible solution to this problem is the infall of pristine neutral gas, potentially initiated during a gravitational interaction. Using archival HI spectral-line imaging obtained with the Karl G. Jansky Very Large Array, we have discovered a previously unknown companion of DDO 68. This low-mass (M$_{\rm HI}$ $=$ 2.8$\times$10$^{7}$ M$_{\odot}$), recently star-forming (SFR$_{\rm FUV}$ $=$ 1.4$\times$10$^{-3}$ M$_{\odot}$ yr$^{-1}$, SFR$_{\rm H\alpha}$ $<$ 7$\times$10$^{-5}$ M$_{\odot}$ yr$^{-1}$) companion has the same systemic velocity as DDO 68 (V$_{\rm sys}$ $=$ 506 km s$^{-1}$; D $=$ 12.74$\pm$0.27 Mpc) and is located at a projected distance of 42 kpc. New HI maps obtained with the 100m Robert C. Byrd Green Bank Telescope provide evidence that DDO 68 and this companion are gravitationally interacting at the present time. Low surface brightness HI gas forms a bridge between these objects.
    04/2014; 787(1).
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    ABSTRACT: In contrast to massive, bulge hosting galaxies, very few supermassive black holes (SMBHs) are known in either low mass, or bulgeless galaxies. Such a population could provide clues to the origins of SMBHs and to secular pathways for their growth. Using the all-sky Wide-Field Infrared Survey Explorer (WISE) survey, and bulge-to-disk decompositions from the Sloan Digital Sky Survey (SDSS) Data Release 7, we report the discovery of a population of local (z<0.3) bulgeless disk galaxies with extremely red mid-infrared colors highly suggestive of a dominant active galactic nucleus (AGN), despite having no optical AGN signatures in their SDSS spectra. Using various mid-infrared selection criteria from the literature, there are between 30 to over 300 bulgeless galaxies with possible AGNs. Other known scenarios that can heat the dust to high temperatures do not appear to explain the observed colors of this sample. If these galaxies are confirmed to host AGNs, this study will provide a breakthrough in characterizing the properties of SMBHs in the low bulge mass regime and in understanding their relation with their host galaxies. Mid-infrared selection identifies AGNs that dominate their host galaxy's emission and therefore reveal a different AGN population than is uncovered by optical studies. We find that the fraction of all galaxies identified as candidate AGNs by WISE is highest at lower stellar masses and drops dramatically in higher mass galaxies, in striking contrast to the findings from optical studies.
    The Astrophysical Journal 01/2014; 784(2). · 6.73 Impact Factor
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    ABSTRACT: The Wide-Field Infrared Sky Survey (WISE) provides a look at the dust emission in galaxies over the entire sky. We match this catalog with SDSS DR7 in order to calculate the luminosity and stellar mass functions for galaxies with z<0.1 as a function of [3.4]-[4.6] micron color. The number density of galaxies with red infrared colors ([3.4]-[4.6] > 0.5) rises toward the low mass and low luminosity end. This increase in the dust emission in lower mass galaxies, which are generally thought to be younger and more pristine, is important to understanding the mechanisms that are driving this emission. Other studies have associated red [3.4]-[4.6] colors with star formation, AGN activity, and shocks. We include the HI 21 cm properties of these galaxies in order to study the impact of the gaseous environment and gas-to-stars ratio on these systems and the mechanisms that might be driving the heating of the dust. This study was funded by NSF grant AST-000167932.
    01/2014;
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    ABSTRACT: "Hα Dots" are compact sources of line emission that were discovered in a narrow-band imaging study of nearby, star-forming galaxies (Kellar et al. 2008, 2012). While located in close angular and velocity proximity to normal star-forming disk galaxies, they are not obviously associated with them. In Allan et al. (2010) we presented preliminary HI spectral line imaging of selected "Hα Dots" obtained with the Karl G. Jansky Very Large Array in the C configuration. Here present preliminary results from subsequent observations of these sources in the D configuration. The increased surface brightness sensitivity of the combined datasets allows us to determine if the Hα Dots are located within the target galaxies’ gas envelopes, within tidal tails, or if they are isolated, extragalactic star-forming objects. We present HI moment maps and compare these to optical broad and narrow-band images of the same fields. JMC is supported by NSF grant AST-1211683.
    01/2014;
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    ABSTRACT: We present new Very Large Array H I spectral line, archival Sloan Digital Sky Survey, and archival Spitzer Space Telescope imaging of eight star-forming blue compact dwarf galaxies that were selected to be optically compact (optical radii <1 kpc). These systems have faint blue absolute magnitudes (M B –17), ongoing star formation (based on emission-line selection by the Hα or [O III] lines), and are nearby (mean velocity = 3315 km s–1 45 Mpc). One galaxy in the sample, ADBS 113845+2008, is found to have an H I halo that extends 58 r-band scale lengths from its stellar body. In contrast, the rest of the sample galaxies have H I radii to optical-scale-length ratios ranging from 9.3 to 26. The size of the H I disk in the "giant disk" dwarf galaxy ADBS 113845+2008 appears to be unusual as compared with similarly compact stellar populations.
    The Astronomical Journal 04/2013; 145(6):150. · 4.97 Impact Factor
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    Nathalie C. Haurberg, Jessica Rosenberg, John J. Salzer
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    ABSTRACT: We have analyzed long-slit spectra of 12 dwarf irregular galaxies from the Arecibo Dual Beam Survey (ADBS). These galaxies represent a heterogeneous sample of objects detected by ADBS, but on average are relatively gas-rich, low-surface-brightness, and low-mass, thus represent a region of the galaxian population that is not commonly included in optical surveys. The metallicity-luminosity relationship for these galaxies is analyzed; the galaxies discussed in this paper appear to be under-abundant at a given luminosity when compared to a sample from the literature. We attempt to identify a "second parameter" responsible for the intrinsic scatter and apparent under-abundance of our galaxies. We do not find a definitive second parameter but note the possible indication that infall or mixing of pristine gas may be responsible. We derive oxygen abundances for multiple HII regions in many of our galaxies but do not find any strong indications of metallicity variation within the galaxies except in one case where we see variation between an isolated HII region and the rest of the galaxy. Our data set includes the galaxy with the largest known HI-to-optical size ratio, ADBS 113845+2008. Our abundance analysis of this galaxy reveals that it is strongly over-enriched compared to galaxies of similar luminosity, indicating it is not a young object and confirming the result from Cannon et. al (2009) that this galaxy appears to be intrinsically rare in the local universe.
    The Astrophysical Journal 01/2013; 765(1). · 6.73 Impact Factor
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    ABSTRACT: We have used the Cosmic Origins Spectrograph (COS) to obtain far-UV spectra of three closely-spaced QSO sight lines that probe the circumgalactic medium (CGM) of an edge-on spiral galaxy, ESO 157-49, at impact parameters of 74 and 93 kpc near its major axis and 172 kpc along its minor axis. H I Ly\alpha\ absorption is detected at the galaxy redshift in the spectra of all three QSOs, and metal lines of Si III, Si IV, and C IV are detected along the two major-axis sight lines. Photoionization models of these clouds suggest metallicities close to the galaxy metallicity, cloud sizes of ~1 kpc, and gas masses of ~10^4 solar masses. Given the high covering factor of these clouds, ESO 157-49 could harbor ~2x10^9 solar masses of warm CGM gas. We detect no metals in the sight line that probes the galaxy along its minor axis, but gas at the galaxy metallicity would not have detectable metal absorption with ionization conditions similar to the major-axis clouds. The kinematics of the major-axis clouds favor these being portions of a "galactic fountain" of recycled gas, while two of the three minor-axis clouds are constrained geometrically to be outflowing gas. In addition, one of our QSO sight lines probes a second more distant spiral, ESO 157-50, along its major axis at an impact parameter of 88 kpc. Strong H I Ly\alpha\ and C IV absorption only are detected in the QSO spectrum at the redshift of ESO 157-50.
    The Astrophysical Journal 01/2013; 765(1). · 6.73 Impact Factor
  • Hans Most, J. M. Cannon, J. J. Salzer, J. L. Rosenberg
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    ABSTRACT: We present Very Large Array H I spectral line and optical imaging of eight optically compact (optical radii <1 kpc), star-forming dwarf galaxies. These galaxies were chosen because of their optically compact stellar distributions, faint blue magnitudes, ongoing star formation, and relative proximity. The sample includes ADBS 113845+2008, which was found to have an HI halo that extends nearly 40 optical scale lengths from the stellar body (Cannon et al. 2009). Using this larger sample, we are working to discern if the "giant gas disk" dwarf galaxy is common or rare. We are also exploring the kinematics and dark matter contents of each of the sample galaxies.
    01/2012;
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    ABSTRACT: We present a current catalog of 21 cm H I line sources extracted from the Arecibo Legacy Fast Arecibo L-band Feed Array (ALFALFA) survey over ~2800 deg2 of sky: the α.40 catalog. Covering 40% of the final survey area, the α.40 catalog contains 15,855 sources in the regions 07h30m < R.A. < 16h30m, +04° < decl. <+16°, and +24° < decl. <+28° and 22h < R.A. < 03h, +14° < decl. <+16°, and +24° < decl. < + 32°. Of those, 15,041 are certainly extragalactic, yielding a source density of 5.3 galaxies per deg2, a factor of 29 improvement over the catalog extracted from the H I Parkes All-Sky Survey. In addition to the source centroid positions, H I line flux densities, recessional velocities, and line widths, the catalog includes the coordinates of the most probable optical counterpart of each H I line detection, and a separate compilation provides a cross-match to identifications given in the photometric and spectroscopic catalogs associated with the Sloan Digital Sky Survey Data Release 7. Fewer than 2% of the extragalactic H I line sources cannot be identified with a feasible optical counterpart; some of those may be rare OH megamasers at 0.16 < z < 0.25. A detailed analysis is presented of the completeness, width-dependent sensitivity function and bias inherent of the α.40 catalog. The impact of survey selection, distance errors, current volume coverage, and local large-scale structure on the derivation of the H I mass function is assessed. While α.40 does not yet provide a completely representative sampling of cosmological volume, derivations of the H I mass function using future data releases from ALFALFA will further improve both statistical and systematic uncertainties.
    The Astronomical Journal 10/2011; 142(5):170. · 4.97 Impact Factor
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    ABSTRACT: We present moderate-resolution Cosmic Origins Spectrograph (COS) far-UV spectra of three QSOs that probe the extended gaseous halo of the nearby spiral galaxy ESO 157-G049 (cz = 1673 km/s; L = 0.1 L*) at impact parameters of 53, 66, and 124 kpc. H I Lyman-alpha absorption is detected at the galaxy redshift in the spectra of all three QSOs and metal lines of Si III, Si IV, and C IV are detected in two of the three spectra. No metals are detected in the sight line that probes ESO 157-G049 along its minor axis at an impact parameter of 124 kpc, implying that there is no galactic wind that reaches these radii. Further, no low ions (i.e., C II, Si II) associated with ESO 157-G049 are detected in any of the QSO spectra so its gaseous halo is highly ionized even at radii of 50 kpc. These spectra allow us to probe the three-dimensional structure of low- and intermediate-ionization gas in nearby galaxy halos for the first time and begin to map the distribution of metals and energy as a function of impact parameter and position angle with respect to the galaxy.
    01/2011;
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    ABSTRACT: We present a study of a large, statistically complete sample of star-forming dwarf galaxies using mid-infrared observations from the {\it Spitzer Space Telescope}. The relationships between metallicity, star formation rate (SFR) and mid-infrared color in these systems show that the galaxies span a wide range of properties. However, the galaxies do show a deficit of 8.0 \um\ polycyclic aromatic hydrocarbon emission as is apparent from the median 8.0 \um\ luminosity which is only 0.004 \lstarf\ while the median $B$-band luminosity is 0.05 \lstarb. Despite many of the galaxies being 8.0 \um\ deficient, there is about a factor of 4 more extremely red galaxies in the [3.6] $-$ [8.0] color than for a sample of normal galaxies with similar optical colors. We show correlations between the [3.6] $-$ [8.0] color and luminosity, metallicity, and to a lesser extent SFRs that were not evident in the original, smaller sample studied previously. The luminosity--metallicity relation has a flatter slope for dwarf galaxies as has been indicated by previous work. We also show a relationship between the 8.0 \um\ luminosity and the metallicity of the galaxy which is not expected given the competing effects (stellar mass, stellar population age, and the hardness of the radiation field) that influence the 8.0 \um\ emission. This larger sample plus a well-defined selection function also allows us to compute the 8.0 \um\ luminosity function and compare it with the one for the local galaxy population. Our results show that below 10$^{9}$ $L$\solar, nearly all the 8.0 \um\ luminosity density of the local universe arises from dwarf galaxies that exhibit strong \ha\ emission -- i.e., 8.0 \um\ and \ha\ selection identify similar galaxy populations despite the deficit of 8.0 \um\ emission observed in these dwarfs. Comment: 13 pages, 11 figures, Published in ApJ
    The Astrophysical Journal 06/2010; · 6.73 Impact Factor
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    ABSTRACT: The Arecibo L-band Feed Array (ALFA) is being used to conduct a low-Galactic latitude survey, to map the distribution of galaxies and large-scale structures behind the Milky Way through detection of galaxies' neutral hydrogen (HI) 21-cm emission. This Zone of Avoidance (ZOA) survey finds new HI galaxies which lie hidden behind the Milky Way, and also provides redshifts for partially-obscured galaxies known at other wavelengths. Before the commencement of the full survey, two low-latitude precursor regions were observed, totalling 138 square degrees, with 72 HI galaxies detected. Detections through the inner Galaxy generally have no cataloged counterparts in any other waveband, due to the heavy extinction and stellar confusion. Detections through the outer Galaxy are more likely to have 2MASS counterparts. We present the results of these precursor observations, including a catalog of the detected galaxies, with their HI parameters. The survey sensitivity is well described by a flux- and linewidth-dependent signal-to-noise ratio of 6.5. ALFA ZOA galaxies which also have HI measurements in the literature show good agreement between our measurements and previous work. The inner Galaxy precursor region was chosen to overlap the HI Parkes Zone of Avoidance Survey so ALFA performance could be quickly assessed. The outer Galaxy precursor region lies north of the Parkes sky. Low-latitude large-scale structure in this region is revealed, including an overdensity of galaxies near l = 183 deg and between 5000 - 6000 km/s in the ZOA. The full ALFA ZOA survey will be conducted in two phases: a shallow survey using the observing techniques of the precursor observations, and also a deep phase with much longer integration time, with thousands of galaxies predicted for the final catalog. Comment: 26 pages, 7 figures, 2 tables, Astronomical Journal accepted
    The Astronomical Journal 02/2010; · 4.97 Impact Factor
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    ABSTRACT: We present preliminary results from a VLA HI spectral line study of optically compact (radii
    01/2010;
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    ABSTRACT: A VLA HI spectral line study of five nearby, optically compact dwarf galaxies has revealed that four of these systems have companion systems in close proximity. Here we explore the morphology and kinematics of these companion systems. Two are massive spirals (NGC 5375, companion of KISSR 396; and NGC 5657, companion of KISSR 561) and two are comparatively under-studied systems (SDSS J131552.81+292515.1, companion of KISSR 245; and SDSS J144754.58+293221.1, companion of KISSR 572). We do not detect extended tidal material at this sensitivity level in any of these systems, suggesting that these interactions have not been close or recent enough to remove large amounts of HI from the systems involved.
    01/2010;
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    ABSTRACT: We present a multi-wavelength study of star-forming dwarf galaxies. All galaxies are selected from the KPNO International Spectroscopic Survey when they exhibit detectable Hα emission. The SFRs computed at different wavelengths are compared to study the effect of the second parameter such as metallicity, gas content, and star formation history.
    01/2010;
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    ABSTRACT: We present preliminary results from a major VLA HI imaging program to discern the nature of "Halpha Dots". These compact sources of line emission were discovered in a narrow-band imaging study of nearby, star-forming galaxies (Kellar, 2008); while located in close angular and velocity proximity to the target galaxies, they are not obviously associated with them. Here we present C-array imaging of selected members of our sample, with the aim of determining whether the Halpha Dots are located within the target galaxies' gas envelopes, within tidal tails, or if they are isolated, extragalactic star-forming objects. Many of the "Halpha Dots" are not detected in HI at this sensitivity level. In the majority of fields with HI-detected Halpha Dots, there is clear evidence of tidal stripping from the target galaxy (though some Halpha Dots are detected in HI that is not tidally disturbed). Further observations of the sample with the VLA in the D configuration will increase our sensitivity to the extended structures surrounding the target galaxies.
    01/2010;
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    John M. Cannon, John J. Salzer, Jessica L. Rosenberg
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    ABSTRACT: We present new optical imaging and spectroscopy and HI spectral line imaging of the dwarf galaxy ADBS 113845+2008 (hereafter ADBS 1138). This metal-poor (Z~30% Z_Sun), "post-starburst" system has one of the most compact stellar distributions known in any galaxy to date (B-band exponential scale length =0.57 kpc). In stark contrast to the compact stellar component, the neutral gas is extremely extended; HI is detected to a radial distance of ~25 kpc at the 10^19 cm^-2 level (>44 B-band scale lengths). Comparing to measurements of similar "giant disk" dwarf galaxies in the literature, ADBS 1138 has the largest known HI-to-optical size ratio. The stellar component is located near the center of a broken ring of HI that is ~15 kpc in diameter; column densities peak in this structure at the ~3.5x10^20 cm^-2 level. At the center of this ring, in a region of comparatively low HI column density, we find ongoing star formation traced by H alpha emission. We sample the rotation curve to the point of turn over; this constrains the size of the dark matter halo of the galaxy, which outweighs the luminous component (stars + gas) by at least a factor of 15. To explain these enigmatic properties, we examine "inside-out" and "outside-in" evolutionary scenarios. Calculations of star formation energetics indicate that "feedback" from concentrated star formation is not capable of producing the ring structure; we posit that this is a system where the large HI disk is evolving in quiescent isolation. In a global sense, this system is exceedingly inefficient at converting neutral gas into stars.
    The Astrophysical Journal 02/2009; · 6.73 Impact Factor
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    ABSTRACT: We report the discovery of a dwarf (MB = -13.9) poststarburst galaxy coincident in recession velocity (within uncertainties) with the highest column density absorber (NH i = 1015.85 cm-2 at cz = 1586 km s-1) in the 3C 273 sight line. This galaxy is by far the closest galaxy to this absorber, projected just 71 h kpc on the sky from the sight line. The mean properties of the stellar populations in this galaxy are consistent with a massive starburst ≈3.5 Gyr ago, whose attendant supernovae, we argue, could have driven sufficient gas from this galaxy to explain the nearby absorber. Beyond its proximity on the sky and in recession velocity, the further evidence in favor of this conclusion includes both a match in the metallicities of absorber and galaxy and the fact that the absorber has an overabundance of Si/C, suggesting recent Type II supernova enrichment. Thus, this galaxy and its ejecta are in the expected intermediate stage in the fading dwarf evolutionary sequence envisioned by Babul & Rees to explain the abundance of faint blue galaxies at intermediate redshifts. While this one instance of a QSO metal-line absorber and a nearby dwarf galaxy is not proof of a trend, a similar dwarf galaxy would be too faint to be observed by galaxy surveys around more distant metal-line absorbers. Thus, we cannot exclude the possibility that dwarf galaxies are primarily responsible for weak (NH i = 1014-1017 cm-2) metal-line absorption systems in general. If a large fraction of the dwarf galaxies expected to exist at high redshift had a similar history (i.e., they had a massive starburst that removed all or most of their gas), these galaxies could account for at least several hundred high-z metal-line absorbers along the line of sight to a high-z QSO. The volume-filling factor for this gas, however, would be less than 1%.
    The Astrophysical Journal 12/2008; 609(1):94. · 6.73 Impact Factor

Publication Stats

692 Citations
217.98 Total Impact Points

Institutions

  • 2007–2014
    • George Mason University
      • • School of Physics, Astronomy, and Computational Sciences
      • • Astrophysics Group
      Fairfax, Virginia, United States
  • 2009
    • Wesleyan University
      • Department of Astronomy
      Middletown, Connecticut, United States
  • 2005–2008
    • Harvard-Smithsonian Center for Astrophysics
      • Smithsonian Astrophysical Observatory
      Cambridge, Massachusetts, United States
    • University of Michigan
      • Department of Astronomy
      Ann Arbor, MI, United States
  • 2003–2008
    • University of Colorado at Boulder
      • • Center for Astrophysics and Space Astronomy
      • • Department of Astrophysical and Planetary Sciences
      Boulder, CO, United States
  • 2000–2007
    • University of Massachusetts Amherst
      • Department of Astronomy
      Amherst Center, MA, United States
  • 2006
    • National Astronomy and Ionosphere Center
      • The Arecibo Observatory
      Arecibo, Arecibo, Puerto Rico
  • 1994
    • Brigham Young University - Hawaii
      Kahuku, Hawaii, United States