Search Publications
Planetary Nebulae catalogue with Gaia EDR3
Dafonte, C.; González-Santamaría, I.; Manteiga, M. +2 more
We have created a new Planetary Nebulae (PNe) catalogue by using astrometric and photometric data from Gaia EDR3. Firstly, we have developed an algorithm that selects the most reliable source from EDR3 to be the Central Star (CS) of each PN, among all sources in the neighbourhood of them. This algorithm considers both the angular distance to PN co…
Possible optical counterparts of ULXs in NGC 1672
Sonbas, Eda; Allak, Sinan; Akyuz, Aysun +1 more
In this study, we use archival data from Hubble Space Telescope (HST), Chandra, XMM‑Newton, and Swift‑XRT, to probe the nature of 9 (X1‑X9) candidate ultraluminous X‑ray sources (ULXs) in NGC 1672. Our study focuses on using the precise source positions obtained via improved astrometry based on Chandra and HST observations to search for and identi…
The Force-freeness of the Solar Photosphere: Revisit with New Approach and Large Data Sets
Zhang, Mei; Zhang, Haocheng
Although it is generally believed that the solar photosphere is not magnetically force-free owing to its high plasma β, the estimations of force-freeness using observed magnetograms have produced disputable results. Some studies confirmed that the photosphere is largely not force-free whereas some authors argued that the photosphere is not far awa…
Novel application to estimate the mass-loss and the dust-formation rates in O-type gamma-ray binaries using near-infrared photometry
Moritani, Yuki; Kawachi, Akiko; Okazaki, Atsuo T. +2 more
We have performed the near-infrared photometric monitoring observations of two TeV gamma-ray binaries with O-stars (LS 5039 and 1FGL J1018.6-5856), using IRSF/SIRIUS at SAAO, in order to study the stellar parameters and their perturbations caused by the binary interactions. The whole orbital phase was observed multiple times and no significant var…
Dynamic Study of the Triple Star T Tauri
Romanenko, L. G.; Kiyaeva, O. V.
The triple system of young stars T Tauri was discovered relatively recently and has attracted the attention of numerous researchers. Many papers have been dedicated to the study of the physical properties of the system's stars, which are surrounded by a disk of dust and gas. Our work is focused on the astrometric analysis of this triple system usi…
Searching for overlooked TDEs in the 4XMM catalogue
Risaliti, Guido; Sacchi, Andrea; Miniutti, Giovanni
Tidal disruption events (TDEs) are usually discovered as bright transients, either in the X‑ray or optical/UV band. These events are often characterized by a "super‑soft" emission in the X‑ray band, which has not been observed in any other extragalactic source, with few exceptions (novae and supersoft active galactic nuclei, AGN), which can howeve…
New Insight into the FS CMa System MWC 645 from Near-Infrared and Optical Spectroscopy
Kraus, Michaela; Arias, María Laura; Eenmäe, Tõnis +2 more
The B[e] phenomenon is manifested by a heterogeneous group of stars surrounded by gaseous and dusty circumstellar envelopes with similar physical conditions. Among these stars, the FS CMa-type objects are suspected to be binary systems, which could be experiencing or have undergone a mass-transfer process that could explain the large amount of mat…
Search of nearby resolved neutron stars among optical sources
Bihain, Gabriel
Neutron stars are identified as pulsars, X-ray binary components, central objects of supernovae remnants, or isolated thermally emitting sources and at distances beyond 120 pc. A population extrapolation suggests 103 objects within that boundary. Potentially, neutron stars could continuously emit gravitational waves at sensitivity reach…
Vela X-1 in depth: a review article on an outstanding object
Degenaar, N.; Utrilla, E.; Ramos-Lerate, M. +9 more
The paper - https://ui.adsabs.harvard.edu/abs/2021A%26A...652A..95K/abstract {Revisiting the archetypical wind accretor Vela X-1 in depth}. Case study of a well-known X-ray binary and the limits of our knowledge - provided a thoughtful compilation of the knowledge of the Vela X-1 system and its modelling published over decades; added new informati…
Formation of a Massive Lenticular Galaxy Under the Tidal Interaction with a Group of Dwarf Galaxies
Zhang, Chuan-Peng; Xu, Jin-Long; Zhu, Ming +6 more
Based on the atomic-hydrogen (H I) observations using the Five-hundred-meter Aperture Spherical radio Telescope, we present a detailed study of the gas-rich massive S0 galaxy NGC 1023 in a nearby galaxy group. The presence of a H I extended warped disk in NGC 1023 indicates that this S0 galaxy originated from a spiral galaxy. The data also suggest…