Search Publications
Revisiting bounds on primordial black hole as dark matter with X-ray background
Tan, Xiu-Hui; Xia, Jun-Qing
Within the mass range of 1016 - 5 × 1018 g, primordial black holes (PBHs) persist as plausible candidates for dark matter. Our study involves a reassessment of the constraints on PBHs through a comparative analysis of the cosmic X-ray background (CXB) and the emissions arising from their Hawking evaporation. We identify previ…
The K2 Asteroseismic KEYSTONE sample of Dwarf and Subgiant Solar-Like Oscillators. I. Data and Asteroseismic parameters
Chaplin, William J.; Davies, Guy R.; Bieryla, Allyson +19 more
Aims: The KEYSTONE project aims to enhance our understanding of solar-like oscillators by delivering a catalogue of global asteroseismic parameters (Δv and vmax) for 173 stars, comprising mainly dwarfs and subgiants, observed by the K2 mission in its short-cadence mode during campaigns 6-19.
Methods: We derive atmospheric para…
He-rich Hot Subdwarf Stars Observed in Gaia DR3 and LAMOST DR7: Carbon and Nitrogen Abundances and Kinematics
Luo, Yangping; Németh, Péter; Wang, Kun +1 more
We conducted an analysis of the abundances of He, C, and N in 210 He-rich hot subdwarfs observed within both the Gaia Data Release 3 (DR3) and LAMOST DR7 data sets. This analysis involved fitting the LAMOST spectra with TLUSTY/SYNSPEC non-LTE synthetic spectra. By examining the Galactic spatial positions, velocity vectors, and orbital parameters o…
The influence of black holes on the binary population of the globular cluster Palomar 5
Pang, Xiaoying; Wang, Long; Li, Chengyuan +3 more
The discovery of stellar-mass black holes (BHs) in globular clusters (GCs) raises the possibility of long-term retention of BHs within GCs. These BHs influence various astrophysical processes, including merger-driven gravitational waves and the formation of X-ray binaries. They also impact cluster dynamics by heating and creating low-density cores…
The properties of supermassive black holes and their host galaxies for type 1 and 2 active galactic nuclei in the eFEDS and COSMOS fields
Georgantopoulos, I.; Mountrichas, G.
In this study, our primary objective is to compare the properties of supermassive black holes (SMBHs) and their host galaxies between type 1 and type 2 active galactic nuclei (AGNs). In our analysis, we use X-ray detected sources in two fields, namely the eFEDS and the COSMOS-Legacy. To classify the X-ray sources, we performed a spectral energy di…
Interplanetary Type IV Solar Radio Bursts: A Comprehensive Catalog and Statistical Results
Mohan, Atul; Gopalswamy, Nat; Kumari, Anshu +2 more
Decameter hectometric (DH; 1–14 MHz) type IV radio bursts are produced by flare-accelerated electrons trapped in postflare loops or the moving magnetic structures associated with the coronal mass ejections (CMEs). From a space weather perspective, it is important to systematically compile these bursts, explore their spectrotemporal characteristics…
Evolution of coronal mass ejections with and without sheaths from the inner to the outer heliosphere: Statistical investigation for 1975 to 2022
Temmer, M.; Larrodera, C.
Aims: This study covers a thorough statistical investigation of the evolution of interplanetary coronal mass ejections (ICMEs) with and without sheaths through a broad heliocentric distance and temporal range. The analysis treats the sheath and magnetic obstacle (MO) separately in order to gain more insight on their physical properties. In de…
HST Proper Motion of Andromeda III. Another Satellite Coorbiting the M31 Satellite Plane
Kozhurina-Platais, Vera; Casetti-Dinescu, Dana I.; Girard, Terrence M. +5 more
We measure the absolute proper motion of Andromeda III (And III) using Advanced Camera for Surveys/Wide Field Channel and WFPC2 exposures spanning an unprecedented 22 yr time baseline. The WFPC2 exposures have been processed using a deep-learning centering procedure recently developed as well as an improved astrometric calibration of the camera. T…
Primordial black holes and scalar-induced gravitational waves from the polynomial attractor model
Wang, Yue; Gong, Yungui; Wang, Zhongkai +1 more
Primordial black holes (PBHs) generated in the early Universe are considered as one of the candidates for dark matter. To produce PBHs with sufficient abundance, the primordial scalar power spectrum needs to be enhanced to the order of 0.01. Considering the third-order polynomial potential with polynomial attractors, we show that PBHs with a mass …
An Empirical Framework Characterizing the Metallicity and Star-formation History Dependence of X-Ray Binary Population Formation and Emission in Galaxies
Greene, Jenny E.; Oskinova, Lidia; Basu-Zych, Antara +12 more
We present a new empirical framework modeling the metallicity and star formation history (SFH) dependence of X-ray luminous (L ≳ 1036 erg s‑1) point-source population X-ray luminosity functions (XLFs) in normal galaxies. We expect that the X-ray point-source populations are dominated by X-ray binaries (XRBs), with contributio…