Search Publications
Photometry and astrometry with JWST‑II: NIRCam distortion correction
Bedin, L. R.; Nardiello, D.; Griggio, M.
In preparation to make the most of our own planned James Webb Space Telescope investigations, we take advantage of publicly available calibration and early‑science observations to independently derive and test a geometric‑distortion solution for NIRCam detectors. Our solution is able to correct the distortion to better than 0.2 mas. Current data i…
Winds in ultraluminous X‑ray sources: New challenges
Pinto, C.; Kosec, P.
Ultraluminous X‑ray sources (ULXs) are extreme X‑ray binaries shining above 1039 erg/s, in most cases as a consequence of super‑Eddington accretion onto neutron stars and stellar‑mass black holes accreting above their Eddington limit. This was understood after the discovery of coherent pulsations, cyclotron lines, and powerful winds. The latter wa…
Gaia search for stellar companions of TESS Objects of Interest IV
Mugrauer, M.; Rück, J.; Michel, K. -U.
We present the latest results of our ongoing multiplicity study of (Community) TESS Objects of Interest, using astrometric and photometric data from the ESA‑Gaia mission to detect stellar companions of these stars and characterize their properties. A total of 134 binary, 6 hierarchical triple, and two quadruple star systems are identified among 11…
XMM2ATHENA, the H2020 project to improve XMM‑Newton analysis software and prepare for Athena
Ballet, Jean; Pouliasis, Ektoras; Maggi, Pierre +31 more
XMM‑Newton, a European Space Agency observatory, has been observing the X‑ray, ultra‑violet, and optical sky for 23 years. During this time, astronomy has evolved from mainly studying single sources to populations and from a single wavelength, to multi‑wavelength/messenger data. We are also moving into an era of time domain astronomy. New software…
The hyperluminous X‑ray source population
Roberts, T. P.; Walton, D. J.; MacKenzie, A. D. A.
We have recently published a catalog of 1843 candidate ultraluminous X‑ray sources (ULXs). This is the largest catalog of ULXs to date and was built by cross‑correlating recent serendipitous source catalogs from the XMM‑Newton, Swift, and Chandra observatories with a large sample of galaxies, primarily from HyperLEDA. The catalog contains 71 hyper…
On the true nature of the contact binary CRTS J192848.7‑404555
Filipović, Miroslav; Wadhwa, Surjit S.; DeHorta, Ain Y. +1 more
CRTS J192848.7‑404555 was recognized as a potential contact binary merger candidate on the basis of survey photometry analysis. We have carried out follow‑up ground‑based photometry of the system and showed that at the recorded coordinates for the system, there are two stars approximately 3 s of arc apart. Our analysis shows that the fainter of th…
Kinematical and ellipsoidal properties of K dwarfs in the solar neighborhood of the Gaia era
Elsanhoury, W. H.; Al-Johani, Amnah S.
The study reports velocity ellipsoid parameters including the kinematical properties of K dwarf stars. Herein, two samples of K dwarf stars are presented with the solar neighborhood ( pc) for high (; 106 points) and low galactic latitudes (; 199 points). We calculated spatial velocities (, , and ; km s) along the galactic coordinates and the veloc…
The Maunakea Spectroscopic Explorer: Thousands of fibers, infinite possibilities
Sobeck, Jennifer; Barden, Samuel C.; Sheinis, Andrew
The Maunakea Spectroscopic Explorer (MSE) is a massively multiplexed spectroscopic survey facility that will replace the Canada–France–Hawai'i Telescope over the next two decades. This 12.5‑m telescope, with its 1.5 square degree field of view, will observe 18,000–20,000 astronomical targets in every pointing from 0.36 to 1.80 m at low/moderate re…
Tidal disruption events and quasi‑periodic eruptions
Lin, Dacheng; Godet, Olivier; Webb, Natalie A. +4 more
Tidal disruption events (TDEs) occur when a star passes close to a massive black hole so that the tidal forces of the black hole exceed the binding energy of a star and cause it to be ripped apart. Part of the matter will fall onto the black hole, causing a strong increase in luminosity. Such events are often seen in the optical or the x‑ray (or b…
The astrophysical parameters of Majaess‑95 and Majaess‑225
Tadross, A. L.
Most astrophysical parameters of the two stellar clusters Majaess 95 and Majaess 225 have been investigated here for the first time using the third data release of the Gaia space mission (Gaia‑DR3). The membership probabilities of stars were assigned using the pyUPMASK algorithm. The parallaxes offset has been corrected using the zero‑point correc…