Search Publications
Enhanced YSO population in Serpens
Saifuddin, Md.; Hasan, S. N.; Hasan, Priya +1 more
Serpens molecular cloud is one of the most active sites of ongoing star formation at a distance of about 300 pc, and hence, is very well-suited for studies of young low-mass stars and sub-stellar objects. In this paper, for the Serpens star-forming region, we found potential members of the Young Stellar Objects (YSOs) population from the Gaia DR3 …
LeMMINGs. V. Nuclear activity and bulge properties: A detailed multi-component decomposition of e-MERLIN Palomar galaxies with HST
Argo, M. K.; Gallagher, J. S.; Knapen, J. H. +12 more
We used high-resolution HST imaging and e-MERLIN 1.5-GHz observations of galaxy cores from the LeMMINGs survey to investigate the relation between optical structural properties and nuclear radio emission for a large sample of galaxies. We performed accurate, multi-component decompositions of new surface brightness profiles extracted from HST image…
Investigating Stellar Variability in the Open Cluster Region NGC 381
Joshi, Y. C.; Panchal, A.; Maurya, Jayanand +1 more
We study variable stars in the field of the open cluster NGC 381 using photometric data observed over 27 nights and identify a total of 57 variable stars, six of which are member stars. The variable stars are classified based on their periods, amplitudes, light-curve shapes, and locations in the H-R diagram. We found a rich variety of variable sta…
Diffuse solar coronal features and their spicular footpoints
Peter, H.; Chitta, L. P.; Milanović, N.
Context. In addition to a component of the emission that originates from clearly distinguishable coronal loops, the solar corona also exhibits extreme-ultraviolet (EUV) and X-ray ambient emission that is rather diffuse and is often considered undesirable background. Importantly, unlike the generally more structured transition region and chromosphe…
A multi-band AGN-SFG classifier for extragalactic radio surveys using machine learning
Wang, L.; Vaccari, M.; Morganti, R. +7 more
Context. Extragalactic radio continuum surveys play an increasingly more important role in galaxy evolution and cosmology studies. While radio galaxies and radio quasars dominate at the bright end, star-forming galaxies (SFGs) and radio-quiet active galactic nuclei (AGNs) are more common at fainter flux densities.
Aims: Our aim is to develop …
VLT-MUSE spectroscopy of AGNs misclassified by BPT diagnostic or with weak emission lines
Janowiecki, Steven; Boquien, Médéric; Salim, Samir +3 more
Despite powerful X-ray emission, some active galactic nuclei (AGNs) are known to either lack optical emission lines (so-called 'optically dull' AGNs) or have lines that fall on the star-forming branch of the Baldwin-Phillips-Terlevich (BPT) diagram ('misclassified' AGNs). Aperture effects have been proposed to explain such atypical spectra, especi…
eRASSt J040515.6 − 745202, an X-ray burster in the Magellanic Bridge
Haberl, F.; Ray, P. S.; Ducci, L. +13 more
Context. During the third all-sky survey (eRASS3), eROSITA, the soft X-ray instrument aboard Spectrum-Roentgen-Gamma, detected a new hard X-ray transient, eRASSt J040515.6 − 745202, in the direction of the Magellanic Bridge.
Aims: We arranged follow-up observations and searched for archival data to reveal the nature of the transient.
Met…
New insights from cross-correlation studies between solar activity indices and cosmic-ray flux during Forbush decrease events
Savić, Mihailo; Veselinović, Nikola; Dragić, Aleksandar +5 more
Observed galactic cosmic ray intensity can be subjected to a transient decrease. These so-called Forbush decreases are driven by coronal mass ejection induced shockwaves in the heliosphere. By combining in situ measurements by space borne instruments with ground-based cosmic ray observations, we investigate the relationship between solar energetic…
Resonant Effects of a Bar on the Galactic Disk Kinematics Perpendicular to Its Plane
Vieira, Katherine; Carraro, Giovanni; Korchagin, Vladimir +2 more
Detailed analysis of kinematics of the Milky Way disk in the solar neighborhood based on the GAIA DR3 catalog reveals the existence of peculiarities in the stellar velocity distribution perpendicular to the galactic plane. We study the influence of resonances—the outer Lindblad resonance and the outer vertical Lindblad resonance—of a rotating bar …
The [O III] Profiles of Far-infrared Active and Inactive Optically Selected Green Valley Galaxies
Pović, Mirjana; Väisänen, Petri; Márquez, Isabel +8 more
We present a study of the [O III] λ5007 line profile in a subsample of eight active galactic nuclei (AGNs) and six non-AGNs in the optically selected green valley at z < 0.5 using long-slit spectroscopic observations obtained with the 11 m Southern African Large Telescope. Gaussian decomposition of the line profile was performed to study its di…