Search Publications

The Stellar Halo of the Galaxy is Tilted and Doubly Broken
DOI: 10.3847/1538-3881/ac97e9 Bibcode: 2022AJ....164..249H

Conroy, Charlie; Ting, Yuan-Sen; Johnson, Benjamin D. +7 more

Modern Galactic surveys have revealed an ancient merger that dominates the stellar halo of our galaxy (Gaia-Sausage-Enceladus, GSE). Using chemical abundances and kinematics from the H3 Survey, we identify 5559 halo stars from this merger in the radial range r Gal = 6-60kpc. We forward model the full selection function of H3 to infer th…

2022 The Astronomical Journal
Gaia 45
Mapping the Galactic Metallicity Gradient with Open Clusters: The State-of-the-Art and Future Challenges
DOI: 10.3390/universe8020087 Bibcode: 2022Univ....8...87S

Cunha, Katia; Spina, Lorenzo; Magrini, Laura

In this paper, we make use of data collected for open cluster members by high-resolution spectroscopic surveys and programmes (i.e., APOGEE, Gaia-ESO, GALAH, OCCASO, and SPA). These data have been homogenised and then analysed as a whole. The resulting catalogue contains [Fe/H] and orbital parameters for 251 Galactic open clusters. The slope of th…

2022 Universe
Gaia 45
Anomalous Flux in the Cosmic Optical Background Detected with New Horizons Observations
DOI: 10.3847/2041-8213/ac573d Bibcode: 2022ApJ...927L...8L

Buratti, Bonnie J.; Singer, Kelsi N.; Schenk, Paul M. +27 more

We used New Horizons LORRI images to measure the optical-band (0.4 ≲ λ ≲ 0.9µm) sky brightness within a high-galactic-latitude field selected to have reduced diffuse scattered light from the Milky Way galaxy (DGL), as inferred from the IRIS all-sky 100 µm map. We also selected the field to significantly reduce the scattered light from …

2022 The Astrophysical Journal
Gaia 45
A Second Planet Transiting LTT 1445A and a Determination of the Masses of Both Worlds
DOI: 10.3847/1538-3881/ac50a9 Bibcode: 2022AJ....163..168W

Butler, R. Paul; Kristiansen, Martti H.; Omohundro, Mark +79 more

LTT 1445 is a hierarchical triple M-dwarf star system located at a distance of 6.86 pc. The primary star LTT 1445A (0.257 M ) is known to host the transiting planet LTT 1445Ab with an orbital period of 5.36 days, making it the second-closest known transiting exoplanet system, and the closest one for which the host is an M dwarf. Using …

2022 The Astronomical Journal
Gaia 45
X-Ray Coronal Properties of Swift/BAT-selected Seyfert 1 Active Galactic Nuclei
DOI: 10.3847/1538-4357/ac45f6 Bibcode: 2022ApJ...927...42K

Ricci, Claudio; Stern, Daniel; Urry, C. Megan +9 more

The corona is an integral component of active galactic nuclei (AGNs) which produces the bulk of the X-ray emission above 1-2 keV. However, many of its physical properties and the mechanisms powering this emission remain a mystery. In particular, the temperature of the coronal plasma has been difficult to constrain for large samples of AGNs, as con…

2022 The Astrophysical Journal
XMM-Newton 45
Godzilla, a monster lurks in the Sunburst galaxy
DOI: 10.1051/0004-6361/202243605 Bibcode: 2022A&A...665A.134D

Diego, J. M.; Kelly, P.; Broadhurst, T. +4 more

We model the strong lensing effect in the galaxy cluster PSZ1 G311.65-18.48 (z = 0.443) with an improved version of the hybrid method WSLAP+. We extend the number of constraints by including the position of critical points, which are combined with the classic positional constraints of the lensed galaxies. We pay special attention to a transient ca…

2022 Astronomy and Astrophysics
eHST 45
STEPARSYN: A Bayesian code to infer stellar atmospheric parameters using spectral synthesis
DOI: 10.1051/0004-6361/202141763 Bibcode: 2022A&A...657A..66T

Montes, D.; González Hernández, J. I.; Tabernero, H. M. +1 more

Context. STEPARSYN is an automatic code written in Python 3.X designed to infer the stellar atmospheric parameters Teff, log g, and [Fe/H] of FGKM-type stars following the spectral synthesis method.
Aims: We present a description of the STEPARSYN code and test its performance against a sample of late-type stars that were observed w…

2022 Astronomy and Astrophysics
Gaia 45
One year of AU Mic with HARPS - I. Measuring the masses of the two transiting planets
DOI: 10.1093/mnras/stac614 Bibcode: 2022MNRAS.512.3060Z

Owen, James E.; Aigrain, Suzanne; Gandolfi, Davide +11 more

The system of two transiting Neptune-sized planets around the bright, young M-dwarf AU Mic provides a unique opportunity to test models of planet formation, early evolution, and star-planet interaction. However, the intense magnetic activity of the host star makes measuring the masses of the planets via the radial velocity (RV) method very challen…

2022 Monthly Notices of the Royal Astronomical Society
Gaia 44
The Recent LMC-SMC Collision: Timing and Impact Parameter Constraints from Comparison of Gaia LMC Disk Kinematics and N-body Simulations
DOI: 10.3847/1538-4357/ac4e90 Bibcode: 2022ApJ...927..153C

Choi, Yumi; van der Marel, Roeland P.; Nidever, David L. +4 more

We present analysis of the proper-motion (PM) field of the red clump stars in the Large Magellanic Cloud (LMC) disk using the Gaia Early Data Release 3 catalog. Using a kinematic model based on old stars with 3D velocity measurements, we construct the residual PM field by subtracting the center-of-mass motion and internal rotation motion component…

2022 The Astrophysical Journal
Gaia 44
Luminous Supernovae: Unveiling a Population between Superluminous and Normal Core-collapse Supernovae
DOI: 10.3847/1538-4357/ac9842 Bibcode: 2022ApJ...941..107G

Berger, Edo; Nicholl, Matt; Hosseinzadeh, Griffin +2 more

Stripped-envelope core-collapse supernovae can be divided into two broad classes: the common Type Ib/c supernovae (SNe Ib/c), powered by the radioactive decay of 56Ni, and the rare superluminous supernovae (SLSNe), most likely powered by the spin-down of a magnetar central engine. Up to now, the intermediate regime between these two pop…

2022 The Astrophysical Journal
Gaia 44