Search Publications
Comprehensive X-ray and multiwavelength study of ULXs in NGC 1566
Allak, Sinan
This paper presents a comprehensive X-ray and multiwavelength study of ultraluminous X-ray sources (ULXs) in NGC 1566 using archival Chandra, Swift/XRT, JWST, and HST observations. The main results are, first, from the hardness ratio diagram, where spectral state transitions from hard to soft as seen in typical Galactic high-mass X-ray binaries fo…
Asteroseismology of the mild Am δ Sct star HD 118660: TESS photometry and modelling
Goswami, Aruna; Joshi, Santosh; Semenko, Eugene +9 more
We present the results of an asteroseismic study of HD 118660 (TIC 171729860), being a chemically peculiar (mild Am) star exhibiting
Ionized X-ray winds in the radio galaxy Mrk 6
Fukazawa, Yasushi; Mao, Junjie; Kayanoki, Taishu
Active galactic nucleus (AGN) outflows including jets and ionized winds have been key phenomena such as jet collimation and AGN feedback to the host galaxy in astrophysics. Radio galaxies, a type of AGN with misaligned jets, have provided valuable insights into the properties and relationships of these outflows. However, several aspects regarding …
Ring nebulae around Wolf-Rayet stars in M33 as seen by SITELLE
Drissen, Laurent; Robert, Carmelle; Rousseau-Nepton, Laurie +5 more
We have conducted an analysis of nebulae around Wolf-Rayet (WR) stars in M33 using data collected by the imaging Fourier transform spectrometer SITELLE at the Canada-France-Hawaii telescope as part of the SIGNALS Large Program. Of the 211 known WR stars in M33, 178 are located in the fields observed in this study. We present the results of this an…
Novel constraints on companions to the Helix nebula central star
Lothringer, Joshua D.; Parsons, Steven G.; Rauch, Thomas +3 more
The Helix is a visually striking and the nearest planetary nebula, yet any companions responsible for its asymmetric morphology have yet to be identified. In 2020, low-amplitude photometric variations with a periodicity of 2.8 d were reported based on Cycle 1 TESS observations. In this work, with the inclusion of two additional sectors, these peri…
The first ground-based detection of the 752 GHz water line in local ultraluminous infrared galaxies using APEX-SEPIA
Aalto, Susanne; Martín, Sergio; Zhang, Zhi-Yu +10 more
We report the first ground-based detection of the water line p-H2O (211-202) at 752.033 GHz in three z < 0.08 ultraluminous infrared galaxies (ULIRGs): IRAS 06035-7102, IRAS 17207-0014, and IRAS 09022-3615. Using the Atacama Pathfinder EXperiment (APEX), with its Swedish-ESO PI Instrument for APEX (SEPIA) band-9…
HD 222237 b: a long-period super-Jupiter around a nearby star revealed by radial-velocity and Hipparcos-Gaia astrometry
Butler, R. Paul; Rice, Malena; Wittenmyer, Robert A. +16 more
Giant planets on long-period orbits around the nearest stars are among the easiest to directly image. Unfortunately these planets are difficult to fully constrain by indirect methods, e.g. transit and radial velocity (RV). In this study, we present the discovery of a super-Jupiter, HD 222237 b, orbiting a star located
Probing the energy and luminosity-dependent spectro-timing properties of RX J0440.9+4431 with AstroSat
Paul, Biswajit; Ratheesh, Ajay; Sharma, Rahul +3 more
The Be/X-ray binary pulsar RX J0440.9+4431 went through a giant outburst in December 2022 with a peak flux of
Cassini's CDA observes a variety of dust populations just outside Saturn's main rings
Postberg, Frank; Hillier, Jon K.; Srama, Ralf +5 more
Before the end of its mission, the Cassini spacecraft orbited Saturn in a series of highly inclined elliptical 'Ring-Grazing' orbits (RGO). During the RGO, the spacecraft passed repeatedly through the ring plane outside the F ring, near the orbits of Janus and Epimetheus, at an average relative speed of ~20 km s-1. For the first time, C…
The chemical diversity of the metal-poor Milky Way
Hawkins, Keith; Jofré, Paula; Yates, Robert M. +2 more
We present a detailed study of the chemical diversity of the metal-poor Milky Way using data from the GALAH DR3 survey. Considering 17 chemical abundances relative to iron ([X/Fe]) for 9923 stars, we employ principal component analysis (PCA) and extreme deconvolution (XD) to identify 10 distinct stellar groups. This approach, free from chemical or…