2021-W46-47

# 2111.07899
- https://arxiv.org/abs/2111.07899
- **SRG/eROSITA view of X-ray reflection in the Central Molecular Zone: a snapshot in September-October 2019**
- This paper shows the result of SRG/eROSITA commissioning observations on the Central Molecular Zone. A hard X-ray (4-8 keV) flux of Sgr A complex ~ 4e-13 erg/s/cm^2/arcmin^2 and upper limits of other complexes are given out. Clear differences in the morphology of the Sgr A complex diffuse emission have been detected. A further high resolution imaging and polarimetric observation is necessary cosidering the scientific significance of these X-ray reflections off dense molecular clouds in probing the past activities of the central SMBH Sgr A*.
- by **华子乾**

# 2111.07925
- https://arxiv.org/abs/2111.07925
- **NGC 1850 BH1 is another stripped-star binary masquerading as a black hole**
- NGC 1850 BH1 is reported as an BH(~11Ms) candidate in NGC 1850 discovered in LMC. Based on the color-magnitude diagram (CMD) and orbital parameters, the donor was inferred as a subgaint with M~5Ms, and the unseen companion was argued to be an BH from the spectra and CMD position. (Saracino et al.(2021))
- This paper shows that the variable star can not be a subgaint with 5Ms, but instead be 1Ms stripped star. Since a 5Ms star would be too compact to produce the observed ellipsoidal distortion. And they explore the evolutionary scenarios that could reprouduce its properties, in which a ∼ 5 Ms primary loses most of its envelope to a companion.
- by **鲍通**

# 2111.10388
- https://arxiv.org/abs/2111.10388
- **The AGN Fraction in Dwarf Galaxies from eROSITA: First Results and Future Prospects**
- by **喻历明**

# 2111.10451
- https://arxiv.org/abs/2111.10451
- **A Swift study of long-term changes in the X-ray flaring properties of Sagittarius A\***
- As the SMBH locates in the Galactic center, Sgr A\* has always been a fascinating target for astrophysical studies. Flaring emission above a steady qiuescent emission has been detected in both X-ray and NIR bands. This paper uses 2006-2019 Swift observations to shed light on the flaring properties of Sgr A\* and try to understand the natural origin of such flares. The authors come to a conclusion that the flaring rate has changed in recent years. More active flaring events can be due to the passing of gaseous objects.
- by **华子乾**

# 2111.12595
- https://arxiv.org/abs/2111.12595
- **Daily variability at milli-arcsecond scales in the radio quiet NLSy1 Mrk 110**
- For the first time, the authors show evidence for significant radio variability at 5 GHz at milli-arcsecond scales on days to weeks time scales in the highly accreting and extremely radio-quiet (RQ) Narrow Line Seyfert 1 (NLSy1) Mrk110.
The short-term radio variability suggests that the GHz emitting region has a size smaller than ~180 Schwarzschild radii.
- by **黄健**

方正42

导航

最近发表

友情链接