Search Publications

Effective temperatures of red supergiants estimated from line-depth ratios of iron lines in the YJ bands, 0.97-1.32µm
DOI: 10.1093/mnras/staa3855 Bibcode: 2021MNRAS.502.4210T

Kobayashi, Naoto; Matsunaga, Noriyuki; Kawakita, Hideyo +10 more

Determining the effective temperatures (Teff) of red supergiants (RSGs) observationally is important in many fields of stellar physics and galactic astronomy, yet some significant difficulties remain as a result of the model uncertainty, which originates mainly in the extended atmospheres of RSGs. Here we propose a line-depth ratio (LDR…

2021 Monthly Notices of the Royal Astronomical Society
Gaia 22
High Mass-Ratio Binary Population in Open Clusters: Segregation of Early Type Binaries and an Increasing Binary Fraction with Mass
DOI: 10.3847/1538-3881/ac2571 Bibcode: 2021AJ....162..264J

Jadhav, Vikrant V.; Subramaniam, Annapurni; Roy, Kaustubh +1 more

Binary stars play a vital role in astrophysical research, as a good fraction of stars are in binaries. Binary fraction (BF) is known to change with stellar mass in the Galactic field, but such studies in clusters require binary identification and membership information. Here, we estimate the total and spectral-type high-mass-ratio (HMR) BF (f

2021 The Astronomical Journal
Gaia 22
Solo dwarfs II: the stellar structure of isolated Local Group dwarf galaxies
DOI: 10.1093/mnras/stab002 Bibcode: 2021MNRAS.503..176H

Côté, P.; Battaglia, G.; Lewis, G. F. +5 more

The Solo (Solitary Local) Dwarf Galaxy survey is a volume-limited, wide-field g- and i-band survey of all known nearby (<3 Mpc) and isolated (>300 kpc from the Milky Way or M31) dwarf galaxies. This set of 44 dwarfs is homogeneously analysed for quantitative comparisons to the satellite dwarf populations of the Milky Way and M31. In this pap…

2021 Monthly Notices of the Royal Astronomical Society
Gaia 22
A Chandra and HST View of WISE-selected AGN Candidates in Dwarf Galaxies
DOI: 10.3847/1538-4357/abfe0c Bibcode: 2021ApJ...914..133L

Greene, Jenny E.; Hainline, Kevin N.; Stern, Daniel +2 more

Reliably identifying active galactic nuclei (AGNs) in dwarf galaxies is key to understanding black hole (BH) demographics at low masses and constraining models for BH seed formation. Here we present Chandra X-ray Observatory observations of 11 dwarf galaxies that were chosen as AGN candidates using Wide-field Infrared Survey Explorer (WISE) mid-in…

2021 The Astrophysical Journal
eHST 22
The HD 98800 quadruple pre-main sequence system. Towards full orbital characterisation using long-baseline infrared interferometry
DOI: 10.1051/0004-6361/202141985 Bibcode: 2021A&A...655A..15Z

Bayo, A.; Olofsson, J.; Haubois, X. +8 more

Context. HD 98800 is a young (∼10 Myr old) and nearby (∼45 pc) quadruple system, composed of two spectroscopic binaries orbiting around each other (AaAb and BaBb), with a gas-rich disk in polar configuration around BaBb. While the orbital parameters of BaBb and AB are relatively well constrained, this is not the case for AaAb. A full characterisat…

2021 Astronomy and Astrophysics
Gaia 22
Dissecting the Supercritical Filaments Embedded in the 0.5 pc Subsonic Region of Barnard 5
DOI: 10.3847/1538-4357/abd6ef Bibcode: 2021ApJ...909...60S

Caselli, Paola; Pineda, Jaime E.; Arce, Héctor G. +7 more

We characterize in detail the two ∼0.3 pc long filamentary structures found within the subsonic region of Barnard 5. We use combined Robert C. Byrd Green Bank Telescope and Very Large Array observations of the molecular lines NH3(1,1) and (2,2) at a resolution of 1800 au, as well as James Clerk Maxwell Telescope continuum observations a…

2021 The Astrophysical Journal
Herschel 22
Extended Tidal Tails of IC 4756 Detected by Gaia EDR3
DOI: 10.3847/1538-3881/ac1f1f Bibcode: 2021AJ....162..171Y

Zhao, Gang; Yang, Yong; Ye, Xianhao +2 more

We report the discovery of emerged tidal tails around open cluster IC 4756 (~1 Gyr) based on 644 members identified from Gaia EDR3. Three-dimensional spatial positions and two-dimensional tangential velocities $\left(x,y,z,\kappa \cdot {\mu }_{\alpha }^{* }/\varpi ,\kappa \cdot {\mu }_{\delta }/\varpi \right)$ are utilized to determine the comovin…

2021 The Astronomical Journal
Gaia 22
Study of the hydrogen escape rate at Mars during martian years 28 and 29 from comparisons between SPICAM/Mars express observations and GCM-LMD simulations
DOI: 10.1016/j.icarus.2019.113498 Bibcode: 2021Icar..35313498C

Lopez-Valverde, M. A.; Forget, F.; Montmessin, F. +10 more

We have simulated the 3D atomic hydrogen density in the Martian upper atmosphere and associated Jeans escape rate during Martian years 28 and 29. The coronal Lyman-α brightness is computed using a 3D radiative transfer model which accounts for the monthly average hydrogen density for these two years and is compared to a large set of observations b…

2021 Icarus
MEx 22
The McDonald Accelerating Stars Survey (MASS): White Dwarf Companions Accelerating the Sun-like Stars 12 Psc and HD 159062
DOI: 10.3847/1538-3881/abd243 Bibcode: 2021AJ....161..106B

Cochran, William D.; Endl, Michael; Kratter, Kaitlin M. +7 more

We present the discovery of a white dwarf companion to the G1 V star 12 Psc found as part of a Keck adaptive optics imaging survey of long-term accelerating stars from the McDonald Observatory Planet Search Program. Twenty years of precise radial-velocity monitoring of 12 Psc with the Tull Spectrograph at the Harlan J. Smith telescope reveals a mo…

2021 The Astronomical Journal
Gaia Hipparcos 22
The Photospheric Footpoints of Solar Coronal Hole Jets
DOI: 10.3847/1538-4357/abd5ad Bibcode: 2021ApJ...909..133M

Muglach, K.

We study the photospheric footpoints of a set of 35 coronal jets in a coronal hole as observed by Hinode/EIS. We use SDO/AIA data to coalign the spectroscopic EIS data with SDO/HMI line-of-sight magnetograms and calculate the plane-of-sky flow field using local correlation tracking (LCT) on SDO/HMI white light images. The jets are put into categor…

2021 The Astrophysical Journal
Hinode 22