Search Publications
TESS Asteroseismic Analysis of the Known Exoplanet Host Star HD 222076
Chaplin, William J.; Kane, Stephen R.; Stassun, Keivan G. +22 more
The Transiting Exoplanet Survey Satellite (TESS) is an all-sky survey mission aiming to search for exoplanets that transit bright stars. The high-quality photometric data of TESS are excellent for the asteroseismic study of solar-like stars. In this work, we present an asteroseismic analysis of the red-giant star HD 222076 hosting a long-period (2…
A Comparison of X-Ray Photon Indices among the Narrow- and Broad-line Seyfert 1 Galaxies
Rakshit, Suvendu; Dewangan, Gulab Chand; Ojha, Vineet +1 more
We present a detailed comparative systematic study using a sample of 221 narrow-line Seyfert 1 (NLSy1) galaxies in comparison to a redshift-matched sample of 154 broad-line Seyfert 1 (BLSy1) galaxies based on their observations using ROSAT and/or XMM-Newton in soft X-ray band (0.1-2.0 keV). A homogeneous analysis is carried out to estimate their s…
Three planets transiting the evolved star EPIC 249893012: a hot 8.8-M⊕ super-Earth and two warm 14.7 and 10.2-M⊕ sub-Neptunes
Kuzuhara, M.; Alonso, R.; Erikson, A. +57 more
We report the discovery of a new planetary system with three transiting planets, one super-Earth and two sub-Neptunes, that orbit EPIC 249893012, a G8 IV-V evolved star (M⋆ = 1.05 ± 0.05 M⊙, R⋆ = 1.71 ± 0.04 R⊙, Teff = 5430 ± 85 K). The star is just leaving the main sequence. We combined K2 ph…
First Solar Energetic Particles Measured on the Lunar Far-side
Wang, Yuming; Xu, Zigong; Guo, Jingnan +7 more
On 2019 May 6 the Lunar Lander Neutron & Dosimetry (LND) Experiment on board the Chang'E-4 lander on the far-side of the Moon detected its first solar energetic particle (SEP) event with proton energies up to 21 MeV. Combined proton energy spectra are studied based on the LND, SOHO/EPHIN, and ACE/EPAM measurements, which show that LND could pr…
Far-infrared Photometric Redshifts: A New Approach to a Highly Uncertain Enterprise
Casey, Caitlin M.
This paper presents a new approach to deriving far-infrared (FIR) photometric redshifts for galaxies based on their reprocessed emission from dust at rest-frame FIR through millimeter wavelengths. FIR photometric redshifts ("FIR-z") have been used over the past decade to derive redshift constraints for highly obscured galaxies that lack photometry…
Accretion History of AGNs. II. Constraints on AGN Spectral Parameters Using the Cosmic X-Ray Background
Kirkpatrick, Allison; Marchesi, Stefano; Urry, C. Megan +5 more
We constrain X-ray spectral shapes for the ensemble of active galactic nuclei (AGNs) based on the shape of the cosmic X-ray background (CXB). Specifically, we rule out regions of X-ray spectral parameter space that do not reproduce the CXB in the energy range 1-100 keV. The key X-ray spectral parameters are the photon index, Γ; the cutoff energy, …
ACCESS: Confirmation of No Potassium in the Atmosphere of WASP-31b
Fortney, Jonathan J.; Kirk, James; López-Morales, Mercedes +12 more
We present a new optical (400-950 nm) transmission spectrum of the hot Jupiter WASP-31b (M = 0.48 MJ; R = 1.54 RJ; P = 3.41 days), obtained by combining four transit observations. These transits were observed with IMACS on the Magellan Baade Telescope at Las Campanas Observatory as part of the ACCESS project. We investigate t…
Is Superorbital Modulation in SMC X-1 Caused by Absorption in a Warped Precessing Accretion Disk?
Maitra, Chandreyee; Paul, Biswajit; Pradhan, Pragati
We present a broadband spectral-timing analysis of SMC X-1 at different intensity states of its superorbital variation using 10 Suzaku and 6 Nuclear Spectroscopic Telescope Array (NuSTAR) observations. The spectrum in all the states can be described by an absorbed power law with a high-energy cutoff and a blackbody component along with an iron emi…
The VANDELS survey: Discovery of massive overdensities of galaxies at z > 2. Location of Lyα-emitting galaxies with respect to environment
Bauer, F. E.; Thomas, R.; Bolzonella, M. +19 more
Context. The advent of deep, multi-wavelength surveys, together with the availability of extensive numerical simulations, now allow us for the systematic search and study of (proto)clusters and their surrounding environment as a function of redshift.
Aims: We aim to define the environment and to identify overdensities in the VANDELS Chandra D…
A Real-time Automatic Validation System for Optical Transients Detected by GWAC
Xu, Y.; Wang, J.; Xin, L. P. +4 more
The ground-based wide-angle camera array generates millions of single frame alerts per night. After the complicated and elaborate filters by multiple methods, a couple of dozens of candidates are still needed to be confirmed by follow-up observations in real-time. In order to free scientists from the complex and high-intensity follow-up tasks, we …