Search Publications
Modelling the AM CVn and double detonation supernova progenitor binary system CD-30°11223
Kupfer, Thomas; Deshmukh, Kunal; Bauer, Evan B. +1 more
We present a detailed modelling study of CD-30°11223 (CD-30), a hot subdwarf (sdB)-white dwarf (WD) binary identified as a double detonation supernova progenitor, using the open-source stellar evolution software MESA. We focus on implementing binary evolution models carefully tuned to match the observed characteristics of the system including log …
A photometric in-depth look at the core-collapsed globular cluster NGC 6284
Cadelano, Mario; Pallanca, Cristina; Dalessandro, Emanuele +4 more
High-resolution Hubble Space Telescope (HST) optical observations have been used to perform the deepest photometric study of the poorly studied Galactic globular cluster NGC 6284. The deep colour-magnitude diagram (CMD) that we obtained reaches 6 mag below the main-sequence turnoff. We provide the first determination of the gravitational centre (C…
Gas content and evolution of a sample of YSO associations at d ≲ 3.5 kpc from the Sun
Li, Guang-Xing; Chen, Bing-Qiu; Zhou, Ji-Xuan
Young Stellar Objects (YSO) are newly formed stars from molecular clouds. They stay close to where they were born and serve as good tracers to study gas and star formation. During cloud evolution, young massive stars can disrupt the surrounding gas through stellar feedback, changing the gas distribution. We study the distribution of the gas around…
Unveiling the purely young star formation history of the SMC's northeastern shell from colour-magnitude diagram fitting
Choi, Yumi; Ruiz-Lara, Tomás; Nidever, David L. +12 more
We obtain a quantitative star formation history (SFH) of a shell-like structure ('shell') located in the northeastern part of the Small Magellanic Cloud (SMC). We use the Survey of the MAgellanic Stellar History to derive colour-magnitude diagrams (CMDs), reaching below the oldest main-sequence turnoff, from which we compute the SFHs with CMD-fitt…
Molecular clouds in M51 from high-resolution extinction mapping
Peretto, Nicolas; Smith, Matthew W. L.; Davis, Timothy A. +5 more
Here, we present the cloud population extracted from M51, following the application of our new high-resolution dust extinction technique to the galaxy. With this technique, we are able to image the gas content of the entire disc of M51 down to 5 pc (0.14 arcsec), which allows us to perform a statistical characterization of well-resolved molecular …
Discrete aurora and the nightside ionosphere of Mars: an EMM–MEX conjunction of FUV imaging, ionospheric radar sounding, and suprathermal electron measurements
Holmström, Mats; Futaana, Yoshifumi; Harada, Yuki +7 more
Since 2021, a new surge in discrete aurora detections at Mars has been observed by the Emirates Mars Ultraviolet Spectrometer (EMUS) onboard the Emirates Mars Mission (EMM) Hope Orbiter as EMUS started to regularly obtain synoptic auroral images with a high sensitivity. Here we report on a fortuitous conjunction between EMM and Mars Express (MEX) …
Contemporaneous X-Ray Observations of 30 Bright Radio Bursts from the Prolific Fast Radio Burst Source FRB 20220912A
Kaspi, Victoria M.; Bhardwaj, Mohit; Scholz, Paul +21 more
We present an extensive contemporaneous X-ray and radio campaign performed on the repeating fast radio burst (FRB) source FRB 20220912A for 8 weeks immediately following the source's detection by CHIME/FRB. This includes X-ray data from XMM-Newton, NICER, and Swift, and radio detections of FRB 20220912A from CHIME/Pulsar and Effelsberg. We detect …
Investigating the long secondary period phenomenon with the ASAS-SN and Gaia data
Pawlak, Michał; Mowlavi, Nami; Eyer, Laurent +1 more
Aims: The aim of this work is to create a complete list of sources exhibiting a long secondary period (LSP) in the ASAS-SN catalog of variable stars, and analyze the properties of this sample compared to other long period variables without an LSP.
Methods: We used the period-amplitude diagram to identify the 55 572 stars showing an LSP, …
A binary system in the S cluster close to the supermassive black hole Sagittarius A*
Eckart, Andreas; Zajaček, Michal; Labadie, Lucas +4 more
High-velocity stars and peculiar G objects orbit the central supermassive black hole (SMBH) Sagittarius A* (Sgr A*). Together, the G objects and high-velocity stars constitute the S cluster. In contrast with theoretical predictions, no binary system near Sgr A* has been identified. Here, we report the detection of a spectroscopic binary system in …
Indications of an offset merger in Abell 3667
Okabe, N.; Simionescu, A.; Fujita, Y. +13 more
Context. Cluster mergers are the most energetic events, releasing kinetic energies of up to 1064 erg and involving megaparsec(Mpc)-scale shocks in their intra-cluster medium (ICM). In merging clusters, cold fronts are frequently observed, which are characterized by temperature and density jumps while maintaining constant pressure. They,…