Search Publications
PeVatron candidate SNR G106.3+2.7 in a low-density cavity: a multiwavelength test
Liu, Ruo-Yu; Chen, Yang; Ge, Chong +1 more
In this paper, we constrain the density of the interstellar medium (ISM) around the hadronic PeVatron candidate, supernova remnant (SNR) G106.3+2.7, based on X-ray and γ-ray observations. The purpose of this investigation is to understand the influence of the gaseous environment on this SNR as a proton PeVatron candidate. By modelling the self-reg…
VLBI astrometry of radio stars to link radio and optical celestial reference frames: observing strategies
Sun, Yan; Zhang, Bo; Chen, Wen +12 more
The Gaia celestial reference frame (Gaia-CRF) will benefit from a close assessment with independent methods, such as Very Long Baseline Interferometry (VLBI) measurements of radio stars at bright magnitudes. However, obtaining full astrometric parameters for each radio star through VLBI measurements demands a significant amount of observation time…
NuSTAR and Swift observations of two supergiant fast X-ray transients: AX J1841.0-0536 and SAX J1818.6-1703
Romano, P.; Ferrigno, C.; Bozzo, E.
Supergiant fast X-ray transients are wind-fed binaries hosting neutron star accretors, which display a peculiar variability in the X-ray domain. Different models have been proposed to explain this variability and the strength of the compact object magnetic field is generally considered a key parameter to discriminate among possible scenarios. We p…
N2H+(1-0) as a tracer of dense gas in and between spiral arms
Moore, T. J. T.; Clark, P. C.; Ragan, S. E. +2 more
Recent advances in identifying giant molecular filaments in Galactic surveys allow us to study the interstellar material and its dense, potentially star forming phase on scales comparable to resolved extragalactic clouds. Two large filaments detected in the 13CO/C18O(J = 3-2) Heterodyne Inner Milky Way Plane Survey (CHIMPS) s…
Imaging and spectroscopic observations of a confined solar filament eruption with two-stage evolution
Xu, Zhe; Xue, Zhike; Yan, Xiaoli +3 more
Solar filament eruptions are often characterized by stepwise evolution due to the involvement of multiple mechanisms, such as magnetohydrodynamic instabilities and magnetic reconnection. In this article, we investigated a confined filament eruption with a distinct two-stage evolution by using the imaging and spectroscopic observations from the Int…
Identification of A-type supergiants from LAMOST DR5
Liu, Chao; Liu, Zhicun; Cui, Wenyuan +7 more
We present a new method for selecting A-type supergiants (A-SGs hereafter) in the LAMOST DR5 data set using the line indices, and identify 40 spectra of 30 A-SG candidates. Based on the analysis of the absolute magnitude of Gaia DR3, SIMBAD data base, ZTF light variation data, and spectral characteristics of A-SGs, we classified the 30 A-SG candid…
LAMOST J040901.83+329355.6 - a new Galactic star with Wolf-Rayet characteristics in the transitional stage from post-asymptotic giant branch to central star of a planetary nebula
Karpov, Sergey; Maryeva, Olga; Moiseev, Alexei +2 more
The similarity in physical conditions in the winds of low-mass post-asymptotic giant branch stars and evolved massive stars leads to the appearance of an interesting phenomenon of spectral mimicry. Because of this, the discovery of every new star with a Wolf-Rayet (WR) spectrum requires a special study of its evolutionary status before it can be i…
First joint X-ray solar microflare observations with NuSTAR and Solar Orbiter/STIX
Krucker, Säm; Jeffrey, Natasha L. S.; Grefenstette, Brian W. +5 more
We present the first joint spectral and imaging analysis of hard X-ray (HXR) emission from three microflares observed by the Nuclear Spectroscopic Telescope ARray (NuSTAR) and Solar Orbiter/Spectrometer/Telescope for Imaging X-rays (STIX). We studied 5 joint spectra from GOES A7, B1, and B6 class microflares from active region AR12765 on 2020 June…
Close binary fractions in accreted and in situ halo stars
Belokurov, Vasily; Bashi, Dolev; Hodgkin, Simon
The study of binary stars in the Galactic halo provides crucial insights into the dynamical history and formation processes of the Milky Way. In this work, we aim to investigate the binary fraction in a sample of accreted and in situ halo stars, focusing on short-period binaries. Utilizing data from Gaia Data Release 3 (DR3), we analysed the radia…
A dusty rain falls on the nova V959 Monocerotis
Evans, A.; Banerjee, D. P. K.; Varricatt, W. P. +1 more
We present archival and ground-based infrared observations of the γ-ray-emitting nova V959 Mon, covering the period 100-4205 d after the 2012 eruption. We use these data to determine that the secondary in the nova system is a G5 main sequence star. Data from the NEOWISE survey reveal a significant increase in the emission at 3.4 and 4.6 $\, \mu$m …