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CAHA/PPAK Integral-field Spectroscopic Observations of M81. II. Testing Photoionization Models in a Spatially Resolved LINER
Li, Zhiyuan; García-Benito, Rubén; Li, Zongnan +1 more
The origin of the low-ionization nuclear emission-line region (LINER) prevalent in local galaxies and its relationship with supermassive black holes have been debated for decades. We perform a comprehensive evaluation of traditional photoionization models against the circumnuclear ionized gas in M81, for which recent CAHA/PPAK integral-field spect…
BV Photometric Observations of the Dwarf Novae DX And and AR And
Zamanov, R. K.; Dankova, L.; Kostov, A.
We report photometric observations of the intranight variability of the dwarf novae DX And and AR And in two bands (B and V) on a few nights in late October 2022. The observations are performed with the 50/70 cm Schmidt telescope of the National Astronomical Observatory Rozhen. The results indicate that both stars exhibit intranight variability wi…
Characterization of intermediate mass young stars from spectral energy distributions and Gaia EDR3
Guzmán-Díaz, J.
Herbig Ae/Be objects (HAeBes) are young, intermediate-mass stars surrounded by protoplanetary disks. From the point of view of star and planet formation, these objects have crucial characteristics. First, their stellar parameters, such as mass or temperature, are between those belonging to the low-mass and high-mass regimes. Second, the presence o…
The Dependence of Iron-rich Metal-poor Star Occurrence on Galactic Environment Supports an Origin in Thermonuclear Supernova Nucleosynthesis
Reggiani, Henrique; Schlaufman, Kevin C.; Reeves, Zachary
It has been suggested that a class of chemically peculiar metal-poor stars called iron-rich metal-poor (IRMP) stars formed from molecular cores with metal contents dominated by thermonuclear supernova nucleosynthesis. If this interpretation is accurate, then IRMP stars should be more common in environments where thermonuclear supernovae were impor…
VarIabiLity seLection of AstrophysIcal sources iN PTF (VILLAIN). I. Structure function fits to 71 million objects
Hjorth, J.; Bruun, S. H.; Agnello, A.
Context. Light-curve variability is well-suited to characterising objects in surveys with high cadence and a long baseline. This is especially relevant in view of the large datasets to be produced by the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST).
Aims: We aim to determine variability parameters for objects in the Paloma…
X-ray Properties of the Luminous Quasar PG 1634+706 at z=1.337 from SRG and XMM-Newton Data
Gilfanov, M. R.; Sunyaev, R. A.; Sazonov, S. Yu. +2 more
In the fall of 2019, during the in-flight calibration phase of the SRG observatory, the onboard eROSITA and Mikhail Pavlinsky ART-XC telescopes carried out a series of observations of PG 1634+706 — one of the most luminous (an X-ray luminosity ${∼}10^{46}$ erg s${}^{-1}$) quasars in the Universe at $z<2$. Approximately at the same dates this qu…
Samanyolu Galaksisinin I. ve III. Çeyreğindeki Açık Kümelerin Dinamik Evrimi
Çakmak, Hikmet
Samanyolu Galaksi'sinin genel dinamiksel özellikleri, galaksinin I. ve III. çeyreğinde metal bolluğu ve radyal hızları bilinen birkaç örnek açık yıldız kümesinin kinematik ve dinamik parametreleri yardımıyla ortaya konulmaya çalışılmıştır. Bu amaçla I. çeyrekte Berkeley 45, NGC 6802 ve Ruprecht 143, III. çeyrekte NGC 2194, NGC 2266 ve NGC 2304 açı…
Analysis of X-Ray Emission from OB Stars. IV. About X-Ray Emission from Inhomogeneous Winds of OB Stars
Ryspaeva, Elizaveta; Kholtygin, Alexander
We study the origin of X-ray emission from OB stars due to collisions of stellar winds and/or inhomogeneities in the winds. The low-resolution X-ray spectra of a big sample of OB stars were fitted by both the stationary APEC/MEKAL models and by this model with an additional PSHOCK component describing the nonstationary X-ray emission. These spectr…
A joint measurement of galaxy luminosity functions and large-scale field densities during the Epoch of Reionization
Furlanetto, Steven R.; Trapp, A. C.
One of the most exciting advances of the current generation of telescopes has been the detection of galaxies during the epoch of reionization, using deep fields that have pushed these instruments to their limits. It is essential to optimize our analyses of these fields in order to extract as much information as possible from them. In particular, s…
Solar Energetic-Particle-Associated Coronal Mass Ejections Observed by the Mauna Loa Solar Observatory Mk3 and Mk4 Coronameters
St. Cyr, O. C.; Thompson, B. J.; Burkepile, J. T. +2 more
We report on the first comprehensive study of the coronal mass ejections (CMEs) associated with ∼25 MeV solar energetic-proton (SEP) events in 1980 - 2013 observed in the low/inner corona by the Mauna Loa Solar Observatory (MLSO) Mk3 and Mk4 coronameters. Where possible, these observations are combined with space-based observations from the Solar …