Search Publications
Identification confusion and blending concealment in the SDSS-DR16 Quasar catalogues - 40 new quasars and 82 false quasars identified
Flesch, Eric Wim
The SDSS-DR16 Quasar Superset and pipeline catalogues are searched for undeclared quasars that were concealed by or confused with other objects, usually due to incomplete deblending. 40 such quasars with redshifts are found and herewith presented. Also, 82 entries in the SDSS-DR16Q main quasar catalogue are shown to be non-quasars, some also due t…
Multiband Imaging of the HD 36546 Debris Disk: A Refined View from SCExAO/CHARIS
Henning, Thomas; Currie, Thayne; Kwon, Jungmi +21 more
We present the first multiwavelength (near-infrared; 1.1-2.4 µm) imaging of HD 36546's debris disk, using the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system coupled with the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS). As a 3-10 Myr old star, HD 36546 presents a rare opportunity to study a debris disk at…
Identifying Candidate Optical Variables Using Gaia Data Release 2
Strader, Jay; Andrew, Shion; Swihart, Samuel J.
Gaia is undertaking a deep synoptic survey of the Galaxy, but photometry from individual epochs has, as of yet, only been released for a minimal number of sources. We show that it is possible to identify variable stars in Gaia Data Release 2 by selecting stars with unexpectedly large photometric uncertainties given their brightness and number of o…
Comparison of light-time formulations in the post-Newtonian framework for the BepiColombo MORE experiment
Cappuccio, Paolo; di Stefano, Ivan; Cascioli, Gael +1 more
The ESA/JAXA BepiColombo mission, launched on 20 October 2018, is currently in cruise toward Mercury. The Mercury Orbiter Radio-science Experiment (MORE), one of the 16 experiments of the mission, will exploit range and range-rate measurements collected during superior solar conjunctions to better constrain the post-Newtonian parameter γ. The MORE…
Multi-messenger astronomy with INTEGRAL
Mereghetti, Sandro; Götz, Diego; Kuulkers, Erik +19 more
At the time of defining the science objectives of the INTernational Gamma-Ray Astrophysics Laboratory (INTEGRAL), such a rapid and spectacular development of multi-messenger astronomy could not have been predicted, with new impulsive phenomena becoming accessible through different channels. Neutrino telescopes have routinely detected energetic neu…
Evolution of timing and spectral characteristics of 4U 1901+03 during its 2019 outburst using the Swift and NuSTAR observatories
Maitra, Chandreyee; Beri, Aru; Girdhar, Tinku +1 more
We report the results from a detailed timing and spectral study of a transient X-ray pulsar, 4U 1901+03 during its 2019 outburst. We performed broadband spectroscopy in the 1-70 $\rm keV$ energy band using four observations made with Swift and NuSTAR at different intensity levels. Our timing results reveal the presence of highly variable pulse pro…
Star Formation in a Strongly Magnetized Cloud
Caselli, Paola; Arce, Héctor G.; Tan, Jonathan C. +6 more
We study star formation in the Center Ridge 1 (CR1) clump in the Vela C giant molecular cloud, selected as a high column density region that shows the lowest level of dust continuum polarization-angle dispersion, likely indicating that the magnetic field is relatively strong. We observe the source with the Atacama Large Millimeter/submillimeter Ar…
A search for runaway stars in 12 Galactic supernova remnants
Mugrauer, Markus; Lux, Oliver; Bischoff, Richard +1 more
Runaway stars can result from core collapse supernovae in multiple stellar systems. If the supernova disrupts the system, the companion is ejected with its former orbital velocity. A clear identification of a runaway star can yield the time and place of the explosion, as well as orbital parameters of the pre supernova binary system. Previous searc…
Probing the Disk-Corona Systems and Broad-line Regions of Changing-look Quasars with X-Ray and Optical Observations
Green, Paul J.; Anderson, Scott F.; Eracleous, Michael +8 more
"Changing-look" quasars are a new class of highly variable active galactic nuclei that have changed their spectral type over surprisingly short timescales of just a few years. The origin of this phenomenon is debated, but is likely to reflect some change in the accretion flow. To investigate the disk-corona systems in these objects, we measure opt…
The Star Formation History of a Post-starburst Galaxy Determined from Its Cluster Population
Chandar, Rupali; French, K. Decker; Mok, Angus +2 more
The recent star formation histories (SFHs) of post-starburst galaxies have been determined almost exclusively from detailed modeling of their composite starlight. This has provided important but limited information on the number, strength, and duration of bursts of star formation. In this work, we present a direct and independent measure of the re…