Search Publications
Discovery of a Dusty, Chemically Mature Companion to a z ∼ 4 Starburst Galaxy in JWST ERS Data
Spoon, Henrik; Stacey, Gordon; Vishwas, Amit +6 more
We report the discovery of two companion sources to a strongly lensed galaxy SPT0418-47 ("ring") at redshift 4.225, targeted by the JWST Early Release Science program. We confirm that these sources are at a similar redshift to the ring based on Hα detected in the NIRSpec spectrum and [C II] λ158 µm line from the Atacama Large Millimeter/subm…
Witnessing the fragmentation of a filament into prestellar cores in Orion B/NGC 2024
André, Ph.; Arzoumanian, D.; Könyves, V. +3 more
Context. Recent Herschel observations of nearby molecular clouds have shown that filamentary structures are ubiquitous and that most prestellar cores form in dense filaments. Probing the detailed density and velocity structure of molecular filaments is therefore crucial for improving our observational understanding of the star formation process. <…
First Observations of the Brown Dwarf HD 19467 B with JWST
Johnstone, Doug; Leisenring, Jarron; Huber, Daniel +21 more
We observed HD 19467 B with JWST's NIRCam in six filters spanning 2.5–4.6 µm with the long-wavelength bar coronagraph. The brown dwarf HD 19467 B was initially identified through a long-period trend in the radial velocity of the G3V star HD 19467. HD 19467 B was subsequently detected via coronagraphic imaging and spectroscopy, and characteri…
Discovery of Two Polars from a Crossmatch of ZTF and the SRG/eFEDS X-Ray Catalog
Riddle, Reed; Szkody, Paula; Mróz, Przemek +14 more
Magnetic cataclysmic variables (CVs) are luminous Galactic X-ray sources, which have been difficult to find in purely optical surveys due to their lack of outburst behavior. The eROSITA telescope on board the Spektr-RG mission is conducting an all-sky X-ray survey and recently released the public eROSITA Final Equatorial Depth Survey (eFEDS) catal…
Late-time Hubble Space Telescope Observations of AT 2018cow. II. Evolution of a UV-bright Underlying Source 2-4 Yr Post-discovery
Kilpatrick, Charles D.; Drout, Maria R.; Foley, Ryan J. +4 more
In this second of a two-paper series, we present a detailed analysis of three Hubble Space Telescope observations taken ~2-4 yr post-discovery, examining the evolution of a UV-bright underlying source at the precise position of AT 2018cow. While observations at ~2-3 yr post-discovery revealed an exceptionally blue (L ν ∝ ν 1.99
Understanding the Early Stages of Galaxy Formation Using Very Metal-poor Stars from the Hamburg/ESO Survey
Carollo, Daniela; Christlieb, Norbert; Tissera, Patricia B. +1 more
We explore the chemodynamical properties of a sample of very metal-poor (VMP) stars selected from the Hamburg/ESO survey, matched with Gaia EDR3, in the phase space identified by the three integrals of motion (L z , E, I 3). Disk and halo orbits are separated by using the criteria defined in Carollo & Chiba. We found 26 …
ATOMIUM: Probing the inner wind of evolved O-rich stars with new, highly excited H2O and OH lines
Menten, K. M.; Kervella, P.; Müller, H. S. P. +17 more
Context. Water (H2O) and the hydroxyl radical (OH) are major constituents of the envelope of O-rich late-type stars. Transitions involving energy levels that are rotationally or vibrationally highly excited (energies ≳4000 K) have been observed in both H2O and OH. These and more recently discovered transitions can now be obse…
Beating Stellar Systematic Error Floors Using Transit-based Densities
Eastman, Jason D.; Diamond-Lowe, Hannah; Tayar, Jamie
It has long been understood that the light curve of a transiting planet constrains the density of its host star. That fact is routinely used to improve measurements of the stellar surface gravity and has been argued to be an independent check on the stellar mass. Here we show how the stellar density can also dramatically improve the precision of t…
Spectroscopic Analysis of Milky Way Outer Halo Satellites: Aquarius II and Boötes II
Li, Ting S.; Simon, Joshua D.; Pace, Andrew B. +3 more
In this paper, we present a chemical and kinematic analysis of two ultrafaint dwarf galaxies (UFDs), Aquarius II (Aqu II) and Boötes II (Boo II), using Magellan/IMACS spectroscopy. We present the largest sample of member stars for Boo II (12), and the largest sample of red giant branch members with metallicity measurements for Aqu II (eight). In b…
Numerical studies on the link between radioisotopic signatures on Earth and the formation of the Local Bubble. II. Advanced modelling of interstellar 26Al, 53Mn, 60Fe, and 244Pu influxes as traces of past supernova activity in the solar neighbourhood
Schulreich, M. M.; Feige, J.; Breitschwerdt, D.
Context. Measurements of long-lived radioisotopes, which have grown rapidly in quantity and sensitivity over the last few years, provide a means, completely independent of other observational channels, to draw conclusions about near-Earth supernovae (SNe) and thus the origin of the Local Bubble (LB), our Galactic habitat. First and foremost in thi…