Search Publications

An ALMA Survey of H2CO in Protoplanetary Disks
DOI: 10.3847/1538-4357/ab64d9 Bibcode: 2020ApJ...890..142P

Wilner, David J.; Cleeves, L. Ilsedore; Andrews, Sean M. +13 more

H2CO is one of the most abundant organic molecules in protoplanetary disks and can serve as a precursor to more complex organic chemistry. We present an Atacama Large Millimeter/submillimeter Array survey of H2CO toward 15 disks covering a range of stellar spectral types, stellar ages, and dust continuum morphologies. H2…

2020 The Astrophysical Journal
Gaia 62
SN 2019ehk: A Double-peaked Ca-rich Transient with Luminous X-Ray Emission and Shock-ionized Spectral Features
DOI: 10.3847/1538-4357/ab9e66 Bibcode: 2020ApJ...898..166J

Pál, András; Kilpatrick, Charles D.; Coulter, David A. +64 more

We present panchromatic observations and modeling of the Calcium-rich supernova (SN) 2019ehk in the star-forming galaxy M100 (d ≈ 16.2 Mpc) starting 10 hr after explosion and continuing for ∼300 days. SN 2019ehk shows a double-peaked optical light curve peaking at t = 3 and 15 days. The first peak is coincident with luminous, rapidly decaying Swif…

2020 The Astrophysical Journal
eHST 62
Millimeter-wave Point Sources from the 2500 Square Degree SPT-SZ Survey: Catalog and Population Statistics
DOI: 10.3847/1538-4357/ab9df7 Bibcode: 2020ApJ...900...55E

Chapman, S.; Bleem, L. E.; Stalder, B. +45 more

We present a catalog of emissive point sources detected in the SPT-SZ survey, a contiguous 2530 square degree area surveyed with the South Pole Telescope (SPT) from 2008-2011 in three bands centered at 95, 150, and 220 GHz. The catalog contains 4845 sources measured at a significance of 4.5σ or greater in at least one band, corresponding to detect…

2020 The Astrophysical Journal
AKARI Herschel 62
Massive Warm/Hot Galaxy Coronae. II. Isentropic Model
DOI: 10.3847/1538-4357/ab7ffc Bibcode: 2020ApJ...893...82F

Faerman, Yakov; Sternberg, Amiel; McKee, Christopher F.

We construct a new analytic phenomenological model for the extended circumgalactic material (CGM) of L* galaxies. Our model reproduces the O VII/O VIII absorption observations of the Milky Way (MW) and the O VI measurements reported by the COS-Halos and eCGM surveys. The warm/hot gas is in hydrostatic equilibrium in an MW gravitational potential, …

2020 The Astrophysical Journal
eHST 61
MINESweeper: Spectrophotometric Modeling of Stars in the Gaia Era
DOI: 10.3847/1538-4357/aba43b Bibcode: 2020ApJ...900...28C

Conroy, Charlie; Ting, Yuan-Sen; Cargile, Phillip A. +4 more

We present MINESweeper, a tool to measure stellar parameters by jointly fitting observed spectra and broadband photometry to model isochrones and spectral libraries. This approach enables the measurement of spectrophotometric distances, in addition to stellar parameters such as Teff, $\mathrm{log}g$, [Fe/H], [α/Fe], and radial velocity.…

2020 The Astrophysical Journal
Gaia 61
The Rotation Curve, Mass Distribution, and Dark Matter Content of the Milky Way from Classical Cepheids
DOI: 10.3847/2041-8213/ab8d45 Bibcode: 2020ApJ...895L..12A

Bird, Sarah A.; Zhao, Gang; Flynn, Chris +1 more

With the increasing number of large stellar survey projects, the quality and quantity of excellent tracers for studying the Milky Way are rapidly growing, one of which is the classical Cepheids. Classical Cepheids are high-precision standard candles with very low typical uncertainties (<3%) available via the mid-infrared period-luminosity relat…

2020 The Astrophysical Journal
Gaia 61
Testing the Kerr Black Hole Hypothesis Using X-Ray Reflection Spectroscopy and a Thin Disk Model with Finite Thickness
DOI: 10.3847/1538-4357/aba625 Bibcode: 2020ApJ...899...80A

Tripathi, Ashutosh; Abdikamalov, Askar B.; Ayzenberg, Dimitry +5 more

X-ray reflection spectroscopy is a powerful tool for probing the strong gravity region of black holes and can be used for testing general relativity in the strong field regime. Simplifications of the available relativistic reflection models limit the capability of performing accurate measurements of the properties of black holes. In this paper, we…

2020 The Astrophysical Journal
Suzaku 61
SN2019dge: A Helium-rich Ultra-stripped Envelope Supernova
DOI: 10.3847/1538-4357/abaa3d Bibcode: 2020ApJ...900...46Y

Kulkarni, S. R.; Duev, Dmitry A.; Rusholme, Ben +28 more

We present observations of ZTF18abfcmjw (SN2019dge), a helium-rich supernova with a fast-evolving light curve indicating an extremely low ejecta mass (≈0.33 M) and low kinetic energy (≈1.3 × 1050 erg). Early-time (<4 days after explosion) photometry reveals evidence of shock cooling from an extended helium-rich envelope o…

2020 The Astrophysical Journal
eHST 61
Caltech-NRAO Stripe 82 Survey (CNSS). III. The First Radio-discovered Tidal Disruption Event, CNSS J0019+00
DOI: 10.3847/1538-4357/abb94b Bibcode: 2020ApJ...903..116A

Cenko, S. B.; Kulkarni, S. R.; Hallinan, G. +8 more

We present the discovery of a nuclear transient with the Caltech-NRAO Stripe 82 Survey (CNSS), a dedicated radio transient survey carried out with the Karl G. Jansky Very Large Array (VLA). This transient, CNSS J001947.3+003527, exhibited a turn-on over a timescale of ≲1 yr, increasing in flux density at 3 GHz from <0.14 mJy in 2014 February to…

2020 The Astrophysical Journal
Gaia 61
Magnetic Reconnection during the Post-impulsive Phase of a Long-duration Solar Flare: Bidirectional Outflows as a Cause of Microwave and X-Ray Bursts
DOI: 10.3847/1538-4357/aba8a6 Bibcode: 2020ApJ...900...17Y

Reeves, Katharine K.; Chen, Bin; Yu, Sijie +5 more

Magnetic reconnection plays a crucial role in powering solar flares, production of energetic particles, and plasma heating. However, where the magnetic reconnections occur, how and where the released magnetic energy is transported, and how it is converted to other forms remain unclear. Here we report recurring bidirectional plasma outflows located…

2020 The Astrophysical Journal
SOHO 61