Search Publications
Solar-Wind High-Speed Stream (HSS) Alfvén Wave Fluctuations at High Heliospheric Latitudes: Ulysses Observations During Two Solar-Cycle Minima
Hajra, Rajkumar; Echer, Ezequiel; Franco, Adriane Marques de Souza +2 more
We study Alfvén wave fluctuations in solar-wind high-speed streams (HSSs) at high heliolatitudes during the last two solar-cycle minima (SCM). Solar-wind plasma and interplanetary magnetic field (IMF) measured by Ulysses during four 50-day intervals in 1994, 1995, 2007, and 2008 were analyzed using wavelet and Fourier analyses, cross-correlation a…
Detection of Martian dust storms using mask regional convolutional neural networks
Gebhardt, Claus; Alshehhi, Rasha
Martian dust plays a crucial role in the meteorology and climate of the Martian atmosphere. It heats the atmosphere, enhances the atmospheric general circulation, and affects spacecraft instruments and operations. Compliant with that, studying dust is also essential for future human exploration. In this work, we present a method for the deep-learn…
The Quasar Luminosity Function at z 5 via Deep Learning and Bayesian Information Criterion
Im, Myungshin; Shin, Suhyun; Kim, Yongjung
Understanding the faint end of quasar luminosity function (LF) at a high redshift is important since the number density of faint quasars is a critical element in constraining ultraviolet (UV) photon budgets for ionizing the intergalactic medium (IGM) in the early universe. Here, we present quasar LF reaching M 1450 ~ -22.0 AB mag at z ~…
The Dust Mass of Supernova Remnants in M31
Ren, Yi; Jiang, Biwei; Zhao, He +2 more
The dust temperature and mass of the supernova remnants (SNRs) in M31 are estimated by fitting the infrared spectral energy distribution calculated from the images in the Spitzer/IRAC4 and MIPS24, Herschel/PACS70, 100, and 160, and Herschel/SPIRE 250 and 350 µm bands. Twenty SNRs with relatively reliable photometry exhibit an average dust te…
The dynamical state of RXCJ1230.7+3439: A multi-substructured merging galaxy cluster
Böhringer, H.; Chon, G.; Barrena, R.
We analyse the kinematical and dynamical state of the galaxy cluster RXCJ1230.7+3439 (RXCJ1230), at z = 0.332 using 93 new spectroscopic redshifts of galaxies acquired at the Telescopio Nazionale Galileo and from SDSS DR16 public data. We study the density galaxy distribution retrieved from photometric SDSS multiband data and find that RXCJ1230 ap…
Detection of highly correlated optical and X-ray variations in SS Cygni with Tomo-e Gozen and NICER
Enoto, Teruaki; Takita, Satoshi; Yamada, Shinya +8 more
We report on simultaneous optical and X-ray observations of the dwarf nova SS Cyg with Tomo-e Gozen/1.05 m Kiso Schmidt and Neutron star Interior Composition ExploreR (NICER)/International Space Station (ISS). A total of four observations were carried out in the quiescent state and highly correlated light variations between the two wavelengths wer…
The first photometric investigation of the poor-thermal contact binary V749 Aurigae
Zhu, Li-Ying; Sarotsakulchai, Thawicharat; Soonthornthum, Boonrucksar +1 more
The multi-filter light curve analysis of V749 Aurigae (thereinafter V0749 Aur) is conducted for the first time. Its orbital period is improved from P = 0.409873 to 0.409890 d in this work. The photometric data from the All-Sky Automated Survey for SuperNovae (ASAS-SN) were utilized to examine the revised orbital period. Then, the phased multi-filt…
A New Detached Binary USNO-B1.0 1421-0485411 with the Secondary Component having Large Albedo
Wang, Xiaobin; Xiang, Yue; Gu, Shenghong +11 more
USNO-B1.0 1421-0485411 is an eclipsing binary system newly discovered in the Yunnan-Hong Kong wide-field photometric survey. Its orbital period is 1.295 days. Based on the V- and R-band photometric data collected at Kunming 1.0 m telescope and spectroscopic data observed at Lijiang 2.4 m telescope, we used the Wilson-Devinney program to determine …
The Impact of Inelastic Collisions with Hydrogen on NLTE Copper Abundances in Metal-poor Stars
Shi, Jianrong; Wang, Xiaofeng; Xu, Xiaodong
We investigate the non-local thermodynamic equilibrium (non-LTE, hereafter NLTE) analysis for Cu I lines with the updated model atom that includes quantum-mechanical rate coefficients of Cu + H and Cu+ + H- inelastic collisions from the recent study of Belyaev et al. The influence of these data on NLTE abundance determination…
A Silent Revolution in Fundamental Astrophysics
Bakış, Volkan; Bilir, Selçuk; Soydugan, Faruk +2 more
Arbitrariness in the zeropoint of bolometric corrections is a paradigm that is nearly a century old and leads to two more paradigms. "Bolometric corrections must always be negative," and "the bolometric magnitude of a star ought to be brighter than its V magnitude". Both were considered valid before the IAU 2015 General Assembly Resolution B2, a r…