R. Cutri

University of Central Florida, Orlando, Florida, United States

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Publications (491)702 Total impact

  • Article: 2016 AA10

    No preview · Article · Jan 2016
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    ABSTRACT: The optical light curve of the quasar PG 1302-102 at $z = 0.278$ shows a strong, smooth 5.2 yr periodic signal, detectable over a period of $\sim 20$ yr. Although the interpretation of this phenomenon is still uncertain, the most plausible mechanisms involve a binary system of two supermassive black holes with a subparsec separation. At this close separation, the nuclear black holes in PG 1302-102 will likely merge within $\sim 10^{5}$ yr due to gravitational wave emission alone. Here we report the rest-frame near-infrared time lags for PG 1302-102. Compiling data from {\it WISE} and {\it Akari}, we confirm that the periodic behavior reported in the optical light curve from Graham et al. (2015) is reproduced at infrared wavelengths, with best-fit observed-frame 3.4 and $4.6 \mu$m time lags of $(2219 \pm 153, 2408 \pm 148)$ days for a near face-on orientation of the torus, or $(4103\pm 153, 4292 \pm 148)$ days for an inclined system with relativistic Doppler boosting in effect. The periodicity in the infrared light curves and the light-travel time of the accretion disk photons to reach the dust glowing regions support that a source within the accretion disk is responsible for the optical variability of PG 1302-102, echoed at the further out dusty regions. The implied distance of this dusty, assumed toroidal region is $\sim$ 1.5 pc for a near face-on geometry, or $\sim$1.1 pc for the relativistic Doppler boosted case.
    Full-text · Article · Nov 2015
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    ABSTRACT: The 163 comets observed during the WISE/NEOWISE prime mission represent the largest infrared survey to date of comets, providing constraints on dust, nucleus size, and CO + CO2 production. We present detailed analyses of the WISE/NEOWISE comet discoveries, and discuss observations of the active comets showing 4.6 μm band excess. We find a possible relation between dust and CO + CO2 production, as well as possible differences in the sizes of long and short period comet nuclei. © 2015. The American Astronomical Society. All rights reserved..
    No preview · Article · Sep 2015 · The Astrophysical Journal
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    ABSTRACT: We present preliminary diameters and albedos for 7956 asteroids detected in the first year of the NEOWISE Reactivation mission. Of those, 201 are near-Earth asteroids and 7755 are Main Belt or Mars-crossing asteroids. 17% of these objects have not been previously characterized using the Near-Earth Object Wide-field Infrared Survey Explorer, or "NEOWISE" thermal measurements. Diameters are determined to an accuracy of ∼20% or better. If good-quality H magnitudes are available, albedos can be determined to within ∼40% or better. © 2015. The American Astronomical Society. All rights reserved.
    Preview · Article · Sep 2015 · The Astrophysical Journal
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    ABSTRACT: We present 20 Wide-field Infrared Survey Explorer (WISE)-selected galaxies with bolometric luminosities L_(bol) > 10^(14) L☉, including five with infrared luminosities L_(IR) ≡ L_((rest 8–1000 μm)) > 10^(14) L☉. These "extremely luminous infrared galaxies," or ELIRGs, were discovered using the "W1W2-dropout" selection criteria which requires marginal or non-detections at 3.4 and 4.6 μm (W1 and W2, respectively) but strong detections at 12 and 22 μm in the WISE survey. Their spectral energy distributions are dominated by emission at rest-frame 4–10 μm, suggesting that hot dust with T_d ~ 450 K is responsible for the high luminosities. These galaxies are likely powered by highly obscured active galactic nuclei (AGNs), and there is no evidence suggesting these systems are beamed or lensed. We compare this WISE-selected sample with 116 optically selected quasars that reach the same L_(bol) level, corresponding to the most luminous unobscured quasars in the literature. We find that the rest-frame 5.8 and 7.8 μm luminosities of the WISE-selected ELIRGs can be 30%–80% higher than that of the unobscured quasars. The existence of AGNs with L_(bol) > 10^(14) L☉ at z > 3 suggests that these supermassive black holes are born with large mass, or have very rapid mass assembly. For black hole seed masses ~10^3 M☉, either sustained super-Eddington accretion is needed, or the radiative efficiency must be <15%, implying a black hole with slow spin, possibly due to chaotic accretion.
    No preview · Article · Jun 2015

  • No preview · Article · Jun 2015
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    ABSTRACT: We present thermal model fits for 11 Jovian and 3 Saturnian irregular satellites based on measurements from the WISE/NEOWISE dataset. Our fits confirm spacecraft-measured diameters for the objects with in situ observations (Himalia and Phoebe) and provide diameters and albedo for 12 previously unmeasured objects, 10 Jovian and 2 Saturnian irregular satellites. The best-fit thermal model beaming parameters are comparable to what is observed for other small bodies in the outer Solar System, while the visible, W1, and W2 albedos trace the taxonomic classifications previously established in the literature. Reflectance properties for the irregular satellites measured are similar to the Jovian Trojan and Hilda Populations, implying common origins.
    No preview · Article · May 2015 · The Astrophysical Journal
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    ABSTRACT: Active galactic nuclei (AGNs) are well-known to exhibit flux variability across a wide range of wavelength regimes, but the precise origin of the variability at different wavelengths remains unclear. To investigate the relatively unexplored near-IR variability of the most luminous AGNs, we conduct a search for variability using well sampled JHKs-band light curves from the 2MASS survey calibration fields. Our sample includes 27 known quasars with an average of 924 epochs of observation over three years, as well as one spectroscopically confirmed blazar (SDSSJ14584479+3720215) with 1972 epochs of data. This is the best-sampled NIR photometric blazar light curve to date, and it exhibits correlated, stochastic variability that we characterize with continuous auto-regressive moving average (CARMA) models. None of the other 26 known quasars had detectable variability in the 2MASS bands above the photometric uncertainty. A blind search of the 2MASS calibration field light curves for AGN candidates based on fitting CARMA(1,0) models (damped-random walk) uncovered only 7 candidates. All 7 were young stellar objects within the {\rho} Ophiuchus star forming region, five with previous X-ray detections. A significant {\gamma}-ray detection (5{\sigma}) for the known blazar using 4.5 years of Fermi photon data is also found. We suggest that strong NIR variability of blazars, such as seen for SDSSJ14584479+3720215, can be used as an efficient method of identifying previously-unidentified {\gamma}-ray blazars, with low contamination from other AGN.
    Preview · Article · Feb 2015 · The Astrophysical Journal
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    ABSTRACT: We have carried out simulations to predict the performance of a new space-based telescopic survey operating at thermal infrared wavelengths that seeks to discover and characterize a large fraction of the potentially hazardous near-Earth asteroid (NEA) population. Two potential architectures for the survey were considered: one located at the Earth-Sun L1 Lagrange point, and one in a Venus-trailing orbit. A sample cadence was formulated and tested, allowing for the self-follow-up necessary for objects discovered in the daytime sky on Earth. Synthetic populations of NEAs with sizes >=140 m in effective spherical diameter were simulated using recent determinations of their physical and orbital properties. Estimates of the instrumental sensitivity, integration times, and slew speeds were included for both architectures assuming the properties of new large-format 10 um detector arrays capable of operating at ~35 K. Our simulation included the creation of a preliminary version of a moving object processing pipeline suitable for operating on the trial cadence. We tested this pipeline on a simulated sky populated with astrophysical sources such as stars and galaxies extrapolated from Spitzer and WISE data, the catalog of known minor planets (including Main Belt asteroids, comets, Jovian Trojans, etc.), and the synthetic NEA model. Trial orbits were computed for simulated position-time pairs extracted from the synthetic surveys to verify that the tested cadence would result in orbits suitable for recovering objects at a later time. Our results indicate that the Earth-Sun L1 and Venus-trailing surveys achieve similar levels of integral completeness for potentially hazardous asteroids larger than 140 m; placing the telescope in an interior orbit does not yield an improvement in discovery rates. This work serves as a necessary first step for the detailed planning of a next-generation NEA survey.
    Full-text · Article · Jan 2015 · The Astronomical Journal
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    ABSTRACT: NASA’s Wide-field Infrared Survey Explorer (WISE) mission, designed to survey the entire sky at infrared wavelengths, has proven a valuable means of discovering and characterizing the small bodies in our solar system. Modifications to the mission’s science data processing system, collectively known as NEOWISE, have allowed new minor planets to be discovered using this space-based infrared telescope. Using radiometric thermal models, physical properties such as diameter and albedo have been derived for more than 158,000 asteroids, including approximately 700 near-Earth objects and 160 comets. Following the conclusion of its primary mission, the WISE spacecraft was placed into hibernation in February 2011. Now renamed NEOWISE, the spacecraft was brought out of hibernation in 2013 to continue the search for near-Earth objects.
    No preview · Chapter · Jan 2015
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    ABSTRACT: The Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) mission observed comet C/2013 A1 (Siding Spring) three times at 3.4 {\mu}m and 4.6 {\mu}m as the comet approached Mars in 2014. The comet is an extremely interesting target since its close approach to Mars in late 2014 will be observed by various spacecraft in-situ. The observations were taken in 2014 Jan., Jul. and Sep. when the comet was at heliocentric distances of 3.82 AU, 1.88 AU, and 1.48 AU. The level of activity increased significantly between the Jan. and Jul. visits but then decreased by the time of the observations in Sep., approximately 4 weeks prior to its close approach to Mars. In this work we calculate Af\r{ho} values, and CO/CO2 production rates.
    Preview · Article · Dec 2014
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    ABSTRACT: M.P.E.C. 2014-U19 Issued 2014 Oct. 18, 16:53 UT The Minor Planet Electronic Circulars contain information on unusual minor planets and routine data on comets. They are published on behalf of Commission 20 of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. Prepared using the Tamkin Foundation Computer Network MPC@CFA.HARVARD.EDU URL http://www.minorplanetcenter.net/ ISSN 1523-6714 2014 TJ64 Observations: K14T64J* S2014 10 07.79182 19 23 38.99 -42 45 15.1 19 RLEU019C51 K14T64J s2014 10 07.79182 1 + 2357.7810 - 4504.7416 - 4647.1640 EU019C51 K14T64J S2014 10 08.05490 19 24 33.00 -42 54 34.2 LEU019C51 K14T64J s2014 10 08.05490 1 + 2382.2213 - 4510.3105 - 4629.2512 EU019C51 K14T64J S2014 10 08.18644 19 25 00.22 -42 59 12.4 LEU019C51 K14T64J s2014 10 08.18644 1 + 2394.4827 - 4513.0890 - 4620.2011 EU019C51 K14T64J S2014 10 08.25215 19 25 13.92 -43 01 32.1 LEU019C51 K14T64J s2014 10 08.25215 1 + 2394.0625 - 4486.5994 - 4646.1564 EU019C51 K14T64J S2014 10 08.31785 19 25 27.58 -43 03 51.0 LEU019C51 K14T64J s2014 10 08.31785 1 + 2393.5302 - 4460.0324 - 4671.9549 EU019C51 K14T64J S2014 10 08.38369 19 25 41.37 -43 06 11.4 LEU019C51 K14T64J s2014 10 08.38369 1 + 2406.3317 - 4489.4520 - 4637.0462 EU019C51 K14T64J S2014 10 08.44939 19 25 55.09 -43 08 29.9 LEU019C51 K14T64J s2014 10 08.44939 1 + 2405.7815 - 4462.9712 - 4662.8387 EU019C51 K14T64J S2014 10 08.51510 19 26 08.93 -43 10 46.9 LEU019C51 K14T64J s2014 10 08.51510 1 + 2405.2429 - 4437.0219 - 4687.8918 EU019C51 K14T64J S2014 10 08.51523 19 26 08.95 -43 10 48.7 LEU019C51 K14T64J s2014 10 08.51523 1 + 2418.7633 - 4492.9528 - 4627.2370 EU019C51 K14T64J S2014 10 08.58093 19 26 22.79 -43 13 07.6 LEU019C51 K14T64J s2014 10 08.58093 1 + 2418.1939 - 4466.5447 - 4653.0456 EU019C51 K14T64J S2014 10 09.04113 19 28 00.60 -43 29 18.0 19 RLEU019C51 K14T64J s2014 10 09.04113 1 + 2440.3301 - 4393.1426 - 4711.0297 EU019C51 K14T64J S2014 10 09.04126 19 28 00.63 -43 29 18.8 LEU019C51 K14T64J s2014 10 09.04126 1 + 2454.5058 - 4449.2184 - 4650.6169 EU019C51 K14T64J S2014 10 09.17267 19 28 28.94 -43 33 54.1 LEU019C51 K14T64J s2014 10 09.17267 1 + 2452.6597 - 4396.3640 - 4701.6038 EU019C51 K14T64J S2014 10 09.30421 19 28 57.35 -43 38 31.3 LEU019C51 K14T64J s2014 10 09.30421 1 + 2465.0183 - 4399.5763 - 4692.1172 EU019C51 K14T64J S2014 10 09.43575 19 29 25.95 -43 43 06.9 LEU019C51 K14T64J s2014 10 09.43575 1 + 2477.4211 - 4402.8375 - 4682.5064 EU019C51 K14T64J S2014 10 09.56716 19 29 54.60 -43 47 41.6 LEU019C51 K14T64J s2014 10 09.56716 1 + 2475.0313 - 4349.9127 - 4732.9884 EU019C51 K14T64J KC2014 10 09.84701019 30 55.10 -43 57 25.8 21.5 RqEU019K93 K14T64J KC2014 10 09.85424619 30 56.65 -43 57 40.3 21.4 RqEU019K93 K14T64J KC2014 10 09.86329919 30 58.57 -43 57 58.8 22.2 RqEU019K93 K14T64J 4C2014 10 10.98527 19 35 13.60 -44 36 54.4 cEU019I11 K14T64J 4C2014 10 10.98611 19 35 13.84 -44 36 56.8 21.5 RcEU019I11 K14T64J 4C2014 10 10.98693 19 35 13.98 -44 36 58.1 21.5 RcEU019I11 K14T64J 4C2014 10 10.98775 19 35 14.14 -44 36 59.9 21.5 RcEU019I11 K14T64J KC2014 10 11.11134119 35 41.62 -44 41 09.2 20.5 RtEU019W86 K14T64J KC2014 10 11.12092119 35 43.79 -44 41 28.0 21.7 RtEU019W86 K14T64J KC2014 10 11.13056719 35 45.99 -44 41 47.2 21.0 RtEU019W86 K14T64J KC2014 10 18.10543420 06 31.93 -48 28 44.6 21.3 RtEU019W86 K14T64J KC2014 10 18.11068220 06 33.45 -48 28 53.7 21.1 RtEU019W86 K14T64J KC2014 10 18.11593020 06 34.97 -48 29 03.0 21.2 RtEU019W86 Observer details: C51 WISE. Measurers A. K. Mainzer, J. M. Bauer, T. Grav, J. R. Masiero, J. W. Dailey, R. M. Cutri, E. L. Wright, C. Nugent, S. Sonnett, R. Stevenson. I11 Gemini South Observatory, Cerro Pachon. Observers J. Masiero, A. Cardwell, E. Wenderoth. Measurer J. Masiero. 8.0-m reflector. K93 Sutherland-LCOGT C. Observer T. Lister. 1.0-m f/8 Ritchey-Chretien + CCD. W86 Cerro Tololo-LCOGT B. Observer T. Lister. 1.0-m f/8 Ritchey-Chretien + CCD. Orbital elements: 2014 TJ64 Earth MOID = 0.1537 AU Epoch 2014 Dec. 9.0 TT = JDT 2457000.5 MPC M 9.36589 (2000.0) P Q n 0.23291111 Peri. 235.12847 +0.92748200 -0.34229560 a 2.6162299 Node 144.20439 +0.36711645 +0.90991332 e 0.5975137 Incl. 14.89729 -0.07072939 +0.23428930 P 4.23 H 21.2 G 0.15 U 6 Residuals in seconds of arc 141007 C51 0.2+ 0.3- 141009 C51 0.2- 0.2- 141010 I11 0.6+ 0.6- 141008 C51 0.2- 0.4- 141009 C51 0.2- 0.5- 141010 I11 0.2+ 0.3- 141008 C51 0.3- 0.4+ 141009 C51 0.2+ 0.3+ 141010 I11 0.0 0.4- 141008 C51 0.2+ 0.1- 141009 C51 0.1- 0.5- 141011 W86 0.2- 0.4- 141008 C51 0.1- 0.0 141009 C51 0.1+ 0.1- 141011 W86 0.1- 0.1- 141008 C51 0.3+ 0.8- 141009 C51 0.4- 0.3+ 141011 W86 0.0 0.2- 141008 C51 0.1- 0.4- 141009 K93 0.1- 0.7+ 141018 W86 0.1+ 0.1+ 141008 C51 0.4+ 1.4+ 141009 K93 0.1- 0.9+ 141018 W86 0.0 0.1+ 141008 C51 0.2+ 0.2+ 141009 K93 0.5- 0.7+ 141018 W86 0.1- 0.0 141008 C51 0.4+ 0.0 141010 I11 0.0 0.0 Ephemeris: 2014 TJ64 a,e,i = 2.62, 0.60, 15 q = 1.0530 Date TT R. A. (2000) Decl. Delta r Elong. Phase V 2014 09 18 18 39 04.2 -30 39 01 0.4262 1.1799 103.5 55.9 21.7 ... 2014 10 03 19 08 48.6 -39 52 45 0.4100 1.1079 94.0 64.3 21.8 ... 2014 10 11 19 35 17.1 -44 37 18 0.4013 1.0806 90.7 67.5 21.8 ... 2014 10 17 20 01 09.2 -47 54 43 0.3949 1.0659 89.0 69.2 21.8 2014 10 18 20 06 01.8 -48 25 30 0.3939 1.0640 88.8 69.4 21.7 2014 10 19 20 11 04.5 -48 55 31 0.3929 1.0622 88.6 69.7 21.7 ... 2014 10 25 20 45 03.9 -51 36 10 0.3872 1.0548 88.0 70.4 21.7 ... 2014 11 02 21 40 11.9 -53 57 14 0.3814 1.0538 88.5 70.3 21.7 ... 2014 11 17 23 39 50.3 -52 37 17 0.3798 1.0789 93.2 66.2 21.6 A. U. Tomatic (C) Copyright 2014 MPC M.P.E.C. 2014-U19
    No preview · Article · Oct 2014
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    ABSTRACT: We present 20 WISE-selected galaxies with bolometric luminosities L_bol > 10^14 L_sun, including five with infrared luminosities L_IR = L(rest 8-1000 micron) > 10^14 L_sun. These "extremely luminous infrared galaxies," or ELIRGs, were discovered using the "W1W2-dropout" selection criteria (Eisenhardt et al. 2012) which requires marginal or non-detections at 3.4 and 4.6 micron (W1 and W2, respectively) but strong detections at 12 and 22 micron in the WISE survey. Their spectral energy distributions are dominated by emission at rest-frame 4-10 micron, suggesting that hot dust with T_d ~ 450K is responsible for the high luminosities. These galaxies are likely powered by highly obscured AGNs, and there is no evidence suggesting these systems are beamed or lensed. We compare this WISE-selected sample with 116 optically selected quasars that reach the same L_bol level, corresponding to the most luminous unobscured quasars in the literature. We find that the rest-frame 5.8 and 7.8 micron luminosities of the WISE-selected ELIRGs can be 30%-80% higher than that of the unobscured quasars. Assuming Eddington-limited accretion, the existence of AGNs with L_bol > 10^14 L_sun at z > 3 places strong constraints on the supermassive black hole growth history, suggesting that these supermassive black holes are born with large mass, or have very rapid mass assembly, possibly by chaotic accretion.
    Full-text · Article · Oct 2014 · The Astrophysical Journal
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    Full-text · Article · Sep 2014
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    ABSTRACT: NASA's Wide-field Infrared Survey Explorer (WISE) spacecraft has been brought out of hibernation and has resumed surveying the sky at 3.4 and 4.6 um. The scientific objectives of the NEOWISE reactivation mission are to detect, track, and characterize near-Earth asteroids and comets. The search for minor planets resumed on December 23, 2013, and the first new near-Earth object (NEO) was discovered six days later. As an infrared survey, NEOWISE detects asteroids based on their thermal emission and is equally sensitive to high and low albedo objects; consequently, NEOWISE-discovered NEOs tend to be large and dark. Over the course of its three-year mission, NEOWISE will determine radiometrically-derived diameters and albedos for approximately 2000 NEOs and tens of thousands of Main Belt asteroids. The 32 months of hibernation have had no significant effect on the mission's performance. Image quality, sensitivity, photometric and astrometric accuracy, completeness, and the rate of minor planet detections are all essentially unchanged from the prime mission's post-cryogenic phase.
    Full-text · Article · Jun 2014 · The Astrophysical Journal
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    ABSTRACT: We present SCUBA-2 (Submillimetre Common-User Bolometer Array) 850 μm submillimetre (submm) observations of the fields of 10 dusty, luminous galaxies at z ∼ 1.7–4.6, detected at 12 and/or 22 μm by the Wide-field Infrared Survey Explorer (WISE) all-sky survey, but faint or undetected at 3.4 and 4.6 μm; dubbed hot, dust-obscured galaxies (Hot DOGs). The six detected targets all have total infrared luminosities greater than 1013 L⊙, with one greater than 1014 L⊙. Their spectral energy distributions (SEDs) are very blue from mid-infrared to submm wavelengths and not well fitted by standard active galactic nuclei (AGN) SED templates, without adding extra dust extinction to fit the WISE 3.4 and 4.6 μm data. The SCUBA-2 850 μm observations confirm that the Hot DOGs have less cold and/or more warm dust emission than standard AGN templates, and limit an underlying extended spiral or ULIRG-type galaxy to contribute less than about 2 or 55 per cent of the typical total Hot DOG IR luminosity, respectively. The two most distant and luminous targets have similar observed submm to mid-infrared ratios to the rest, and thus appear to have even hotter SEDs. The number of serendipitous submm galaxies detected in the 1.5-arcmin-radius SCUBA-2 850 μm maps indicates there is a significant overdensity of serendipitous sources around Hot DOGs. These submm observations confirm that the WISE-selected ultraluminous galaxies have very blue mid-infrared to submm SEDs, suggesting that they contain very powerful AGN, and are apparently located in unusual arcmin-scale overdensities of very luminous dusty galaxies.
    Full-text · Article · Jun 2014 · Monthly Notices of the Royal Astronomical Society
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    ABSTRACT: The Wide-field Infrared Survey Explorer (WISE) spacecraft has been reactivated as NEOWISE-R to characterize and search for Near Earth Objects. The brown dwarf WISE J085510.83-071442.5 has now been reobserved by NEOWISE-R, and we confirm the results of Luhman (2014b), who found a very low effective temperature, a very high proper motion, and a large parallax. The large proper motion has separated the brown dwarf from the background sources that influenced the 2010 WISE data, allowing a measurement of a very red WISE color of W1-W2 > 3.9. A re-analysis of the 2010 WISE astrometry using only the W2 band, combined with the new NEOWISE-R 2014 position, gives an improved parallax of 448 +/- 32 mas and proper motion of 8.072 +/- 0.026 arcsec/yr. These are all consistent with Luhman (2014b).
    Preview · Article · May 2014 · The Astronomical Journal
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    Full-text · Article · Apr 2014
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    Full-text · Article · Apr 2014
  • Article: 2014 HQ124
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    ABSTRACT: Abstract available on the publisher website.
    No preview · Article · Mar 2014

Publication Stats

12k Citations
702.00 Total Impact Points

Institutions

  • 2015
    • University of Central Florida
      • Department of Physics
      Orlando, Florida, United States
    • Planetary Science Institute
      Pasadena, Texas, United States
  • 1999-2015
    • California Institute of Technology
      • • Infrared Processing and Analysis Center
      • • Jet Propulsion Laboratory
      Pasadena, California, United States
  • 2013
    • Johns Hopkins University
      • Applied Physics Laboratory
      Baltimore, Maryland, United States
  • 2012
    • National Radio Astronomy Observatory
      Charlottesville, Virginia, United States
    • University of California, Davis
      Davis, California, United States
    • Harvard-Smithsonian Center for Astrophysics
      • Smithsonian Astrophysical Observatory
      Cambridge, Massachusetts, United States
    • University of Leicester
      • Department of Physics and Astronomy
      Leiscester, England, United Kingdom
  • 2011
    • University of Maryland, College Park
      • Department of Astronomy
      CGS, Maryland, United States
  • 2006
    • Air Force Research Laboratory
      Washington, Washington, D.C., United States
  • 2005
    • University of Virginia
      • Department of Astronomy
      Charlottesville, Virginia, United States
  • 1989-1998
    • University of Massachusetts Amherst
      • Department of Astronomy
      Amherst Center, Massachusetts, United States
  • 1987-1995
    • The University of Arizona
      • Department of Astronomy
      Tucson, Arizona, United States
  • 1993
    • Institute for Advanced Study
      Princeton Junction, New Jersey, United States
  • 1992
    • Princeton University
      • Department of Astrophysical Sciences
      Princeton, New Jersey, United States