Search Publications
Missions
Journals
Publication Years
Considerations for atmospheric retrieval of high-precision brown dwarf spectra
Madhusudhan, Nikku; Piette, Anjali A. A.
Isolated brown dwarfs provide remarkable laboratories for understanding atmospheric physics in the low-irradiation regime, and can be observed more precisely than exoplanets. As such, they provide a glimpse into the future of high-signal-to-noise ratio (SNR) observations of exoplanets. In this work, we investigate several new considerations that a…
Stellar Spins in the Open Cluster NGC 2516
Healy, Brian F.; McCullough, P. R.
Measuring the distribution of stellar spin axis orientations in a coeval group of stars probes the physical processes underlying the stars' formation. In this paper, we use spectrophotometric observations of the open cluster NGC 2516 to determine the degree of spin alignment among its stars. We combine TESS light curves, ground-based spectroscopy …
A 60 kpc Galactic Wind Cone in NGC 3079
Bregman, Joel N.; Yukita, Mihoko; Ptak, Andrew F. +3 more
Galactic winds are associated with intense star formation and active galactic nuclei. Depending on their formation mechanism and velocity, they may remove a significant fraction of gas from their host galaxies, thus suppressing star formation, enriching the intergalactic medium, and shaping the circumgalactic gas. However, the long-term evolution …
Cataloging accreted stars within Gaia DR2 using deep learning
Hopkins, P. F.; Ostdiek, B.; Necib, L. +6 more
Aims: The goal of this study is to present the development of a machine learning based approach that utilizes phase space alone to separate the Gaia DR2 stars into two categories: those accreted onto the Milky Way from those that are in situ. Traditional selection methods that have been used to identify accreted stars typically rely on full 3…
A successful search for intervening 21 cm H I absorption in galaxies at 0.4 < z <1.0 with the Australian square kilometre array pathfinder (ASKAP)
Ellison, Sara L.; Koribalski, Bärbel S.; Lagos, Claudia del P. +6 more
We have used the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope to search for intervening 21 cm neutral hydrogen (H I) absorption along the line of sight to 53 bright radio continuum sources. Our observations are sensitive to H I column densities typical of Damped Lyman Alpha absorbers (DLAs) in cool gas with an H I spin temp…
NuSTAR Discovery of a Compton-thick, Dust-obscured Galaxy: WISE J0825+3002
Tanimoto, Atsushi; Ueda, Yoshihiro; Kawamuro, Taiki +6 more
We report the discovery of a Compton-thick (CT), dust-obscured galaxy at z = 0.89, WISE J082501.48+300257.2 (WISE 0825+3002), observed by the Nuclear Spectroscopic Telescope Array. X-ray analysis with the XCLUMPY model revealed that hard X-ray luminosity in the rest-frame 2-10 keV band of WISE 0825+3002 is L X (2-10 keV) = {4.2}-1.…
Chandra Observations of NGC 7212: Large-scale Extended Hard X-Ray Emission
Elvis, Martin; Fabbiano, G.; Siemiginowska, A. +5 more
Recent observations of nearby Compton thick (CT) active galactic nuclei (AGNs) with Chandra have resolved hard (>3 keV) X-ray emission extending out from the central supermassive black hole to kiloparsec scales, challenging the long-held belief that the characteristic hard X-ray continuum and fluorescent Fe K lines originate in the inner ∼parse…
Search for 7Be in the outbursts of four recent novae
Bonifacio, P.; Hernanz, M.; Molaro, P. +3 more
Following the recent detection of 7Be II in the outburst spectra of classical novae, we report the search for this isotope in the outbursts of four recent bright novae by means of high-resolution Ultraviolet and Visual Echelle Spectrograph (UVES) observations. The 7Be II λλ313.0583, 313.1228 nm doublet resonance lines are det…
An Increase in Small-planet Occurrence with Metallicity for Late-type Dwarf Stars in the Kepler Field and Its Implications for Planet Formation
Cheng, Sihao; Schlaufman, Kevin C.; Lu, Cicero X.
While it is well-established that giant-planet occurrence rises rapidly with host star metallicity, it is not yet clear if small-planet occurrence around late-type dwarf stars depends on host star metallicity. Using the Kepler Data Release 25 planet candidate list and its completeness data products, we explore planet occurrence as a function of me…
TESS light curves of γ Cas stars
Nazé, Yaël; Rauw, Gregor; Pigulski, Andrzej
γ Cas stars constitute a subgroup of Be stars showing unusually hard and bright X-ray emission. In search for additional peculiarities, we analysed the TESS light curves of 15 γ Cas analogues. Their periodograms display broad frequency groups and/or narrow isolated peaks, often superimposed over red noise. The detected signals appear at low freque…