Search Publications
He abundance in NGC 1850 A and B: Are we observing the early stage of the formation of multiple populations in a stellar cluster?
Biazzo, K.; Brocato, E.; Sollima, A. +1 more
We present the results for a sample of B stars in the Large Magellanic Cloud young double stellar cluster NGC 1850 A and NGC 1850 B, as observed with the integral-field spectrograph at the Very Large Telescope, the Multi Unit Spectroscopic Explorer (MUSE). We compare the observed equivalent widths (EWs) of four He lines (4922, 5015, 6678, and 7065…
Asteroseismology of the fast-rotating high-amplitude δ Scuti star V2367 Cygni
Daszyńska-Daszkiewicz, J.; Walczak, P.; Szewczuk, W.
We present the comprehensive analysis of the high-amplitude $\delta$ Sct star V2367 Cygni. First, we perform the frequency analysis for the whole available set of the Kepler and TESS photometry. Most of the frequency peaks are harmonics or combinations of the three known independent frequencies with the highest amplitudes, i.e.$\nu _1=5.661\,06$ d…
Fe II fluorescence in main-sequence K-dwarfs
Eriksson, M.
Main-sequence K-dwarfs possess strong emission in the form of the H I Ly α line. There is a close coincidence between the energy corresponding to the transitions H I 1s-2p and Fe II (5D)5s 4D5/2-(5D)5p 4D5/2. Singly ionized iron has been confirmed being pumped by photo-excitation by…
Search for the wide-orbit massive companion of XO-7b in the follow-up radial-velocity and transit-timing data: no significant clues
Garai, Z.; Pribulla, T.; Komžík, R.
XO-7b is a hot Jupiter transiting a V = 10.52 mag G0V-type star. The planetary system is interesting because the linear slope in the discovery radial-velocity (RV) data indicated a wide-orbit massive companion. In 2020 we started an RV campaign for the system with the main scientific goal to follow-up this linear slope, and to put constraints on t…
Properties of a fading AGN from SDSS-IV MaNGA
Bizyaev, Dmitry; Gu, Qiu-Sheng; Shi, Yong +7 more
We identify a fading AGN SDSS J220141.64+115124.3 from the internal Product Launch-11 (MPL-11) in Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey. The central region with a projected radius of $\sim$2.4 kpc is characterized as LINER-like line ratios while the outskirts extended to $\sim$15 kpc show Seyfert-like line ratios. The …
Formaldehyde observations of the Perseus Molecular Cloud
Li, Dalei; Tang, Xindi; Zhou, Jianjun +8 more
Large-scale observations of the Perseus Molecular Cloud (MC) with Nanshan 26-m telescope are presented using the 6 cm ortho-H2CO (110-111) transition. As a probe of dense gas at low temperatures, the H2CO absorption extends over the main parts of the Perseus MC. A comparison of the H2CO absorp…
Discovery of small ultra-short-period planets orbiting Kepler KG dwarfs with GPU phase folding and deep learning
Ge, Jian; Wang, Kaitlyn; Willis, Kevin +3 more
Of over 5000 exoplanets identified so far, only a few hundred possess sub-Earth radii. The formation processes of these sub-Earths remain elusive, and acquiring additional samples is essential for investigating this unique population. In our study, we employ the GPFC method, a novel GPU phase folding algorithm combined with a convolutional neural …
North-PHASE: studying periodicity, hot spots, accretion stability, and early evolution in young stars in the Northern hemisphere
Mendigutía, I.; Garufi, A.; Ábrahám, P. +17 more
We present the overview and first results from the North-PHASE Legacy Survey, which follows six young clusters for five years, using the 2 deg$^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…
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…