Search Publications
Pavo: Discovery of a Star-forming Dwarf Galaxy Just Outside the Local Group
Strader, Jay; Sand, David J.; Jones, Michael G. +9 more
We report the discovery of Pavo, a faint (M V = -10.0), star-forming, irregular, and extremely isolated dwarf galaxy at D ≈ 2 Mpc. Pavo was identified in Dark Energy Camera Legacy Survey imaging via a novel approach that combines low surface brightness galaxy search algorithms and machine-learning candidate classifications. Follow-up …
A Novel Survey for Young Substellar Objects with the W-band Filter. VI. Spectroscopic Census of Substellar Members and the IMF of the σ Orionis Cluster
Herczeg, Gregory J.; Jose, Jessy; Allers, Katelyn +11 more
Low-mass stars and substellar objects are essential in tracing the initial mass function (IMF). We study the nearby young σ Orionis cluster (d ~ 408 pc, age ~ 1.8 Myr) using deep near-infrared (NIR) photometric data in the J, W, and H bands from WIRCam on the Canada-France-Hawaii Telescope. We use the water absorption feature to select brown dwarf…
A Database of Magnetic and Thermodynamic Properties of Confined and Eruptive Solar Flares
Kazachenko, Maria D.
Solar flares sometimes lead to coronal mass ejections that directly affect Earth's environment. However, a large fraction of flares, including on solar-type stars, are confined flares. What are the differences in physical properties between confined and eruptive flares? For the first time, we quantify the thermodynamic and magnetic properties of h…
Unveiling the Formation of the Massive DR21 Ridge
Schneider, N.; Csengeri, T.; Bontemps, S. +10 more
We present new 13CO (1-0), C18O (1-0), HCO+ (1-0), and H13CO+ (1-0) maps from the IRAM 30 m telescope and a spectrally resolved [C II] 158 µm map observed with the SOFIA telescope toward the massive DR21 cloud. This traces the kinematics from low- to high-density gas in the cloud, which …
300: An ACA 870 µm Continuum Survey of Orion Protostars and Their Evolution
Narang, Mayank; Pokhrel, Riwaj; Fischer, William J. +11 more
We present an 870 µm continuum survey of 300 protostars from the Herschel Orion Protostar Survey using the Atacama Compact Array (ACA). These data measure protostellar flux densities on envelope scales ≤8000 au (20″) and resolve the structure of envelopes with 1600 au (4″) resolution, a factor of 3-5 improvement in angular resolution over ex…
The Oceanus Moving Group: A New 500 Myr Old Host for the Nearest Brown Dwarf
Kiman, Rocio; Faherty, Jacqueline K.; Gagné, Jonathan +5 more
We report the discovery of the Oceanus moving group, a ≈500 Myr old group with 50 members and candidate members at distances 2-50 pc from the Sun, using an unsupervised clustering analysis of nearby stars with Gaia DR3 data. This new moving group includes the nearest brown dwarf WISE J104915.57-531906.1 AB (Luhman 16 AB) at a distance of 2 pc, whi…
A Glimpse of the Stellar Populations and Elemental Abundances of Gravitationally Lensed, Quiescent Galaxies at z ≳ 1 with Keck Deep Spectroscopy
Allen, Rebecca J.; Kacprzak, Glenn G.; Glazebrook, Karl +13 more
Gravitational lenses can magnify distant galaxies, allowing us to discover and characterize the stellar populations of intrinsically faint, quiescent galaxies that are otherwise extremely difficult to directly observe at high redshift from ground-based telescopes. Here, we present the spectral analysis of two lensed, quiescent galaxies at z ≳ 1 di…
Evidence for a Low Lyman Continuum Escape Fraction in Three Massive, Ultraviolet-bright Galaxies at z > 7
Laporte, Nicolas; Katz, Harley; Witten, Callum E. C.
Although low-mass star-forming galaxies are the leading candidates of the reionization process, we cannot conclusively rule out high-mass star-forming galaxies as candidates. While most simulations indicate the former is the best candidate, some models suggest that at z ≥ 6 massive, UV-bright galaxies - "oligarchs" - account for at least 80% of th…
Discovery of a Variable Multiphase Outflow in the X-Ray-emitting Tidal Disruption Event ASASSN-20qc
Tombesi, F.; Kara, E.; Pasham, D. +1 more
Tidal disruption events (TDEs) are exotic transients that can lead to temporary super-Eddington accretion onto a supermassive black hole. Such an accretion mode is naturally expected to result in powerful outflows of ionized matter. However, to date such an outflow has only been directly detected in the X-ray band in a single TDE, ASASSN-14li. Thi…
Hypervelocity Stars Track Back to the Galactic Center in Gaia DR3
Shi, Jianrong; Ma, Jun; Du, Cuihua +2 more
Based on the proper motions and radial velocities from Gaia Data Release 3, we identify two hypervelocity stars (HVSs) that may originate from the Galactic center (GC). We select the candidates by first filtering for all Gaia stars with Galactocentric radial velocities >500 km s-1. We also require the candidates cross the Galactic mi…