Search Publications
An Improved Near-infrared Spectrum of the Archetype Y Dwarf WISEP J182831.08+265037.8
Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R. +8 more
We present a Hubble Space Telescope/Wide-Field Camera 3 near-infrared spectrum of the archetype Y dwarf WISEP 182831.08+265037.8. The spectrum covers the 0.9-1.7 µm wavelength range at a resolving power of λ/Δλ ≈ 180 and is a significant improvement over the previously published spectrum because it covers a broader wavelength range and is un…
One Year in the Life of Young Suns: Data-constrained Corona-wind Model of κ1 Ceti
Kochukhov, Oleg; Güdel, Manuel; Jin, Meng +5 more
The young magnetically active solar-like stars are efficient generators of ionizing radiation in the form of X-ray and extreme-UV (EUV) flux, stellar wind, and eruptive events. These outputs are the critical factors affecting atmospheric escape and chemistry of (exo)planets around active stars. While X-ray fluxes and surface magnetic fields can be…
On the Color-Metallicity Relation of the Red Clump and the Reddening toward the Magellanic Clouds
Riess, Adam G.; Yuan, Wenlong; Casagrande, Luca +2 more
The zero point of the reddening toward the Large Magellanic Cloud (LMC) has been the subject of some dispute. Its uncertainty propagates as a systematic error for methods that measure the extragalactic distance scale through knowledge of the absolute extinction of LMC stars. In an effort to resolve this issue, we used three different methods to ca…
On the Contribution of the X-Ray Source to the Extended Nebular He II Emission in IZW18
Guerrero, M. A.; Ramos-Larios, G.; Kehrig, C. +1 more
Nebular He II emission implies the presence of energetic photons (E ≥ 54 eV). Despite the great deal of effort dedicated to understanding He II ionization, its origin has remained mysterious, particularly in metal-deficient star-forming (SF) galaxies. Unfolding He II-emitting, metal-poor starbursts at z ∼ 0 can yield insight into the powerful ioni…
Evidence Suggesting That 'Oumuamua Is the 30 Myr Old Product of a Molecular Cloud
Hsieh, Cheng-Han; Laughlin, Gregory; Arce, Héctor G.
The appearance of interstellar objects (ISOs) in the solar system-and specifically the arrival of 1I/'Oumuamua-points to a significant number density of free-floating bodies in the solar neighborhood. We review the details of 'Oumuamua's pre-encounter Galactic orbit, which intersected the solar system at very nearly its maximum vertical and radial…
INTEGRAL Limits on Past High-energy Activity from FRB 20200120E in M81
Götz, D.; Mereghetti, S.; Rigoselli, M. +1 more
The repeating fast radio burst FRB 20200120E is located in a globular cluster belonging to the nearby M81 galaxy. Its small distance (3.6 Mpc) and accurate localization make it an interesting target to search for bursting activity at high energies. From 2003 November to 2021 September, the INTEGRAL satellite has obtained an exposure time of 18 Ms …
A Search for Wandering Black Holes in the Milky Way with Gaia and DECaLS
Ting, Yuan-Sen; Strader, Jay; Greene, Jenny E. +6 more
We present a search for "hypercompact" star clusters in the Milky Way using a combination of Gaia and the Dark Energy Camera Legacy Survey (DECaLS). Such putative clusters, with sizes of ~1 pc and containing 500-5000 stars, are expected to remain bound to intermediate-mass black holes (MBH ≈ 103-105 M⊙) …
A Metallicity Study of F, G, K, and M Dwarfs in the Coma Berenices Open Cluster from the APOGEE Survey
Cunha, Katia; Smith, Verne V.; Souto, Diogo
We present a study of metallicities in a sample of main-sequence stars with spectral types M, K, G, and F (Teff ~3200-6500K and log g ~ 4.3-5.0 dex) belonging to the solar neighborhood young open cluster Coma Berenices. Metallicities were determined using the high-resolution (R = λ/Δ λ ~ 22,500) NIR spectra (λ1.51-λ1.69 µm) of the…
The Flare and Warp of the Young Stellar Disk Traced with LAMOST DR5 OB-type Stars
Tian, Hao; Liu, Chao; Zhang, Bo +9 more
We present an analysis of the spatial density structure for the outer disk from 8-14 kpc with the LAMOST DR5 13,534 OB-type stars and observe similar flaring on the north and south sides of the disk, implying that the flaring structure is symmetrical about the Galactic plane, for which the scale height at different Galactocentric distances is from…
The Post-impact Evolution of the X-Ray-emitting Gas in SNR 1987A as Viewed by XMM-Newton
Vink, Jacco; Zhou, Ping; Pühlhofer, Gerd +4 more
Since 1996 the blast wave driven by SN 1987A has been interacting with the dense circumstellar material, which provides us with a unique opportunity to study the early evolution of a newborn supernova remnant (SNR). Based on the XMM-Newton RGS and EPIC-pn X-ray observations from 2007 to 2019, we investigated the post-impact evolution of the X-ray-…