Search Publications
A new sample of super-slowly rotating Ap (ssrAp) stars from the Zwicky Transient Facility survey
Paunzen, E.; Bernhard, K.; Hümmerich, S.
Context. The magnetic chemically peculiar Ap stars exhibit an extreme spread of rotational velocities, the cause of which is not clearly understood. Ap stars with rotation periods of 50 days or longer are know as super-slowly rotating Ap (ssrAp) stars. Photometrically variable Ap stars are commonly termed α2 Canum Venaticorum (ACV) vari…
Spectroscopic Study of Heating Distributions and Mechanisms Using Hinode/EIS
Hara, Hirohisa; Ishigami, Shun; Oba, Takayoshi
Heating distributions along coronal loops are obtained from spectroscopic data with the Hinode/EUV Imaging Spectrometer. The loop half-lengths L half are in the range of 24–107 Mm for our analysis of 18 loops. By using the analytical approximations to 1D hydrostatic numerical calculations of electron temperature T e (s) and …
Measuring 60 pc-scale Star Formation Rate of the Nearby Seyfert Galaxy NGC 1068 with ALMA, HST, VLT/MUSE, and VLA
Saito, Toshiki; Nakanishi, Kouichiro; Ikarashi, Soh +7 more
The star formation rate (SFR) is a fundamental parameter for describing galaxies and inferring their evolutionary course. H II regions yield the best measure of instantaneous SFR in galaxies, although the derived SFR can have large uncertainties depending on tracers and assumptions. We present an SFR calibration for the entire molecular gas disk o…
Strong Localized Pumping of Water Vapor to High Altitudes on Mars During the Perihelion Season
Aoki, S.; Vandaele, A. C.; Daerden, F. +18 more
Here we present water vapor vertical profiles observed with the ExoMars Trace Gas Orbiter/Nadir and Occultation for MArs Discovery instrument during the perihelion and Southern summer solstice season (LS = 240°-300°) in three consecutive Martian Years 34, 35, and 36. We show the detailed latitudinal distribution of H2O at tan…
Discovery of small ultra-short-period planets orbiting Kepler KG dwarfs with GPU phase folding and deep learning
Ge, Jian; Wang, Kaitlyn; Willis, Kevin +3 more
Of over 5000 exoplanets identified so far, only a few hundred possess sub-Earth radii. The formation processes of these sub-Earths remain elusive, and acquiring additional samples is essential for investigating this unique population. In our study, we employ the GPFC method, a novel GPU phase folding algorithm combined with a convolutional neural …
Structural study of graben within the Margaritifer Terra region of Mars
Dasgupta, Dipayan; Kundu, Abhik; Basu, Supratik +1 more
The surface of Mars preserves a variety of structural and geomorphic features such as wrinkle ridges, graben, lobate scarps, impact basins, paleochannels etc., which owe their origin to endogenic processes of deformation as well as meteorite impacts. Graben, which form in extensional stress regimes, are one of the most common structural features i…
North-PHASE: studying periodicity, hot spots, accretion stability, and early evolution in young stars in the Northern hemisphere
Mendigutía, I.; Garufi, A.; Ábrahám, P. +17 more
We present the overview and first results from the North-PHASE Legacy Survey, which follows six young clusters for five years, using the 2 deg$^2$ FoV of the JAST80 telescope from the Javalambre Observatory (Spain). North-PHASE investigates stellar variability on time-scales from days to years for thousands of young stars distributed over entire c…
Connections between central intensity ratio and hot gas properties of early-type galaxies
Ravikumar, C. D.; Vinod, K. T.; Baheeja, C.
We report strong connections between central intensity ratio (CIR) and hot gas properties of Early-type galaxies (ETGs) in the nearby ($D\lt 30\, \mathrm{Mpc}$) Universe. We find new strong correlations between (optical) CIR and X-ray gas luminosity (LX, GAS) as well as X-ray gas temperature (TGAS). These correlations suggest…
Direct imaging and dynamical mass of a benchmark T-type brown dwarf companion to HD 167665
Lutz, D.; Genzel, R.; Sturm, E. +111 more
Context. A low-mass companion potentially in the brown dwarf mass regime was discovered on a ~12 yr orbit (~5.5 au) around HD 167665 using radial velocity (RV) monitoring. Joint RV–astrometry analyses confirmed that HD 167665B is a brown dwarf with precisions on the measured mass of ~4–9%. Brown dwarf companions with measured mass and luminosity a…
Decoding the thermal history of the merging cluster Cygnus A
Simionescu, A.; Wise, M. W.; de Vries, M. N. +1 more
We report on a detailed spatial and spectral analysis of the large-scale X-ray emission from the merging cluster Cygnus A. We use 2.2 Ms Chandra and 40 ks XMM-Newton archival data sets to determine the thermodynamic properties of the intracluster gas in the merger region between the two subclusters in the system. These profiles exhibit temperature…