Search Publications
Space Physics: The Need for a Wider Perspective
André, Mats
We argue that many studies in space physics would benefit from putting a detailed investigation into a wider perspective. Three examples of theoretical and observational studies are given. We argue that space physics should aim to be less of an isolated branch of science. Rather, by putting the scientific space results into a wider perspective the…
A Systematic Study of the Short-term X-Ray Variability of Seyfert Galaxies. I. Diversity of the X-Ray rms Spectra
Jin, Chichuan; Yuan, Weimin; Hu, Jingwei +1 more
The X-ray variability of active galactic nuclei (AGN) carries crucial information about the X-ray radiation mechanism. We performed a systematic study of the X-ray short-term (1-100 ks timescale) variability for a large sample of 78 Seyferts with 426 deep XMM-Newton observations. In this paper, we present the time-averaged spectra and rms spectra …
Detailed analysis of an eccentric TESS binary star with solar-type components: TIC 284613090
Aliçavuş, Fahri
Eclipsing binary stars are significant objects for understanding stellar evolution, stellar population synthesis, and galaxy dynamics. Thanks to the increasing number of high-quality photometric data of space observations, the sensitivity of the fundamental astrophysical parameters (mass M, radius R) has risen and this situation has highlighted th…
MAXI J1535-571 2017 Outburst Seen by INTEGRAL/SPI and Investigating the Origin of Its Hard Tail
Jourdain, E.; Roques, J. P.; Rodi, James
On 2017 September 2 MAXI J1535-571 went into outburst and peaked at ~5 Crab in the 2-20 keV energy range. Early in the flare, the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) performed target of opportunity pointings and monitored the source as it transitioned from the hard state to the soft state. Using quasi-simultaneous observatio…
Hydrological History of a Palaeolake and Valley System on the Planetary Dichotomy in Arabia Terra, Mars
Grindrod, P. M.; Davis, J. M.; Balme, M. +2 more
Hundreds of ancient palaeolake basins have been identified and cataloged on Mars, indicating the distribution and availability of liquid water as well as sites of astrobiological potential. Palaeolakes are widely distributed across the Noachian aged terrains of the southern highlands, but Arabia Terra hosts few documented palaeolakes and even fewe…
Decoding the Bifurcated Red Giant Branch as a Tracer of Multiple Stellar Populations in the Young Large Magellanic Cloud Cluster NGC 2173
Zucker, Daniel B.; de Grijs, Richard; Kamath, Devika +1 more
Multiple stellar populations (MPs) representing star-to-star light-element abundance variations are common in nearly all ancient Galactic globular clusters (GCs). Here we provide the strongest evidence yet that the populous, ~1.7 Gyr old Large Magellanic Cloud cluster NGC 2173 also exhibits light-element abundance variations. Thus, our results sug…
Anisotropic nonthermal motions in the transition region of solar active regions
Peter, Hardi; Xia, Lidong; Huang, Zhenghua +1 more
Context. We study the nonthermal motions in the transition region of active regions (ARs) using center-to-limb observations of Si IV 1394 Å and 1403 Å lines.
Aims: The aim of this study is to investigate the characteristics of nonthermal motions in the transition region of ARs using the center-to-limb measurement.
Methods: We used Interf…
Diffuse Interstellar Bands λ6379, λ6614, and λ6660 in the LAMOST-MRS Spectra
Luo, A. -Li; Hou, Wen; Zhao, Yong-Heng +2 more
Diffuse interstellar bands (DIBs) have always been a mysterious existence in astronomical research. In this work, we provide more DIB samples to slightly uncover this mystery. With the LAMOST medium-resolution survey (MRS) spectra, we detected three DIBs λ6379, λ6614, and λ6660, obviously superimposed on the spectra of 11,003 stars. These spectra …
Radial velocities from far-red spectra of Carina Arm O and early B stars
Drew, J. E.; Blake-Parsons, F.; Mohr-Smith, M.
Massive O and early B stars are important markers of recent star formation and exert a significant influence on their environments during their short lives via photoionization and winds and when they explode as supernovae. In the Milky Way, they can be detected at great distances but often lie behind large dust columns, making detection at short w…
Locating Red Supergiants in the Galaxy NGC 6822
Massey, Philip; Levesque, Emily M.; Neugent, Kathryn F. +1 more
Using archival near-IR photometry, we identify 51 of the K-band brightest red supergiants (RSGs) in NGC 6822 and compare their physical properties with stellar evolutionary model predictions. We first use Gaia parallax and proper motion values to filter out foreground Galactic red dwarfs before constructing a J-K versus K color-magnitude diagram t…