Search Publications
Flares during eclipses of high-mass X-ray binary systems Vela X-1, 4U 1700-37, and LMC X-4
Paul, Biswajit; Paul, K. T.; Jithesh, V. +2 more
In eclipsing X-ray binary systems, the direct X-ray emission is blocked by the companion star during the eclipse. We observe only reprocessed emission that contains clues about the environment of the compact object and its chemical composition, ionization levels, etc. We have found flares in some X-ray binaries during their eclipses. The study of …
Evaluation of the performance of a CdZnTe-based soft γ -ray detector for CubeSat payloads
Parker, Quentin A.; Ritter, Andreas; Pal, Partha Sarathi +4 more
The low-energy γ -ray (0.1-30 MeV) sky has been relatively unexplored since the decommissioning of the COMPTEL instrument on the Compton Gamma-Ray Observatory (CGRO) satellite in 2000. However, the study of this part of the energy spectrum (the "MeV gap") is crucial for addressing numerous unresolved questions in high-energy and multi-messenger as…
Asymmetry of the spectral lines of the coronal hole and quiet Sun in the transition region
Kayshap, Pradeep; Safari, Hossein; Hosseini, Razieh +1 more
The asymmetry of line profiles, i.e. the secondary component, is crucial to understanding the energy release of coronal holes (CH), quiet Sun (QS), and bright points (BPs). We investigate the asymmetry of Si IV 1393.75 Å of the transition-region (TR) line recorded by Interface Region Imaging Spectrograph (IRIS) and co-spatial-temporal Atmospheric …
Mercury's plasma environment after BepiColombo's third flyby
Fränz, Markus; Krüger, Harald; Saito, Yoshifumi +22 more
Understanding Mercury's magnetosphere is crucial for advancing our comprehension of how the solar wind interacts with the planetary magnetospheres. Despite previous missions, several gaps remain in our knowledge of Mercury's plasma environment. Here, we present findings from BepiColombo's third flyby, offering a synoptic view of the large scale st…
Magnetic Fields Observed along the East–West Outflow of IRAS 16293-2422
Pattle, Kate; Sadavoy, Sarah; Looney, Leslie W. +6 more
Magnetic fields likely play an important role in the formation of young protostars. Multiscale and multiwavelength dust polarization observations can reveal the inferred magnetic field from scales of the cloud to core to protostar. We present continuum polarization observations of the young protostellar triple system IRAS 16293-2422 at 89 µm…
Insights on the Optical and Infrared Nature of MAXI J0709-159: Implications for High-Mass X-ray Binaries
Mathew, Blesson; Muneer, S.; Joshi, Santosh +4 more
In our previous study (Bhattacharyya et al., 2022), HD 54786, the optical counterpart of the MAXI J0709-159 system, was identified to be an evolved star, departing from the main sequence, based on comparisons with non-X-ray binary systems. In this paper, using color-magnitude diagram (CMD) analysis for High-Mass X-ray Binaries (HMXBs) and statisti…
ROME/REA: Three-year, Tri-color Timeseries Photometry of the Galactic Bulge
Saha, A.; Mao, S.; Zang, Weicheng +11 more
The Robotic Observations of Microlensing Events/Reactive Event Assessment Survey was a Key Project at Las Cumbres Observatory (hereafter LCO) which continuously monitored 20 selected fields (3.76 sq.deg) in the Galactic Bulge throughout their seasonal visibility window over a three-year period, between 2017 March and 2020 March. Observations were …
The STATiX pipeline for the detection of X-ray transients in three dimensions
Georgakakis, A.; Pierre, M.; Georgantopoulos, I. +3 more
The recent serendipitous discovery of a new population of short duration X-ray transients, thought to be associated with collisions of compact objects or stellar explosions in distant galaxies, has motivated efforts to build up statistical samples by mining X-ray telescope archives. Most searches to date, however, do not fully exploit recent devel…
A cautionary lesson from Gaia systematics: the mono-metallic globular cluster NGC 5904
Bianchini, Paolo; Mastrobuono-Battisti, Alessandra
The study of the chemistry of the stellar populations in globular clusters (GCs) is a fundamental task to unveil their formation in the high-redshift universe and to reconstruct the build-up of our Galaxy. Using metallicity estimates from BP/RP low-resolution Gaia DR3 spectra, a recent work presented the surprizing detection of two stellar populat…
Rotation and Hα Emission in a Young SMC Cluster: A Spectroscopic View of NGC 330
Dupree, Andrea K.; Milone, Antonino P.; Dotter, Aaron +4 more
We present an analysis of high-resolution optical spectra recorded for 30 stars of the split extended main-sequence turnoff of the young (∼40 Myr) Small Magellanic Cloud globular cluster NGC 330. Spectra were obtained with the Michigan/Magellan Fiber System and Magellan Inamori Kyocera Echelle spectrographs located on the Magellan-Clay 6.5 m teles…