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2023.10.13

Multiband gravitatioanl wave observations of stellar binary black holes

<p>The ground-based gravitational wave (GW) observatories discover a population of merging stellar binary black holes (BBHs), which are promising targets for multiband observations by the low-, middle-, and high-frequency GW detectors. We investigate the multiband GW detections of BBHs and demonstrate the advantages of such observations in improving the localization and parameter estimates of the ...</p>

2023.09.22

WALLABY detects two Polar Ring Galaxies

<p>Polar ring galaxies (PRGs) exhibit an extendedring of material oriented perpendicular to the main disk, which provide crucialclues for galaxy evolutionand dynamics, such as galaxy interaction and gas accretion. In the WALLABY Pilot Data Release 1, we found two potential polar ring galaxies: NGC 4632 and NGC 6156. We used the iDaVIE virtual reality software todecompose gas within the disk and ri...</p>

2023.06.30

Revealing the Recycled inflow of the massive galaxies at high redshift

<p>The gas surrounding galaxies is known as the circumgalactic medium (CGM) which is considered to be deeply coupled with the evolution of galaxies. Although lots of works have been done, how galaxies co-evolve with the CGM is still poorly understood. To explore the CGM-galaxy ecosystem, especially the baryon cycle, we conduct observations on the high redshift CGM. First, we study the gas surroun...</p>

2023.06.16

Flow Annealed Kalman Filters: Gradient-free inference for expensive forward models

<p>For many scientific applications the forward model consists of an expensive black-box simulator without easy access to gradients of the forward model. In such a situation, inference can be challenging, with standard gradient-free sampling algorithms requiring an intractably large number of serial model evaluations. In this talk I will introduce the flow annealed Kalman filter for approximate Ba...</p>

2023.06.09

3D Structure and Extinction of Nearby Molecular Clouds

<p>The 3D structure and extinction law are studied for the Taurus, Orion, Perseus and California molecular clouds (MCs) based on the LAMOST and APOGEE spectroscopy. Extinctions are calculated from color excess derived from the Blue Edge methods. In combination with the distance from the Gaia, &nbsp;a 3D extinction map and the structure of these MCs can be retrieved and the clouds that overlap in the sk...</p>

2023.06.02

A LOFAR Look at Bent Double Lobed Radio Sources: Probing Differences in the Properties of Bent Radio AGNs Inside and Outside of High-z Galaxy Clusters

<p>Bent radio AGN, with their classic “C” shaped morphology, are a unique class of radio AGNs. These radio sources are often used as signposts of a dense, gaseous medium, such as the intracluster medium (ICM). However, bent sources are found inside and outside cluster environments, raising the question of how environment impacts bent radio AGN morphology. We analyzed new LOw-Frequency Array Two-...</p>

2023.05.26

The Long-term Monitoring Results of Insight-HXMT in the First 4 yr Galactic Plane Scanning Survey

<p>The first X-ray source catalog of the Insight-HXMT Galactic Plane (∣b∣ &lt; 10°) Scanning Survey (GPSS) is presented based on the data accumulated from 2017 June to 2021 August. The 4 yr limit sensitivities at main energy bands can reach 8.2 × 10-12 erg s-1 cm2 (2-6 keV), 4.21 × 10-11 erg s-1 cm2 (7-40 keV), and 2.78 × 10-11 erg s-1 cm2 (25-100 keV). More than 1300 sources have been monitored at...</p>

2023.05.12

The Evolution of All Stable Isotopes within Galaxies Across Cosmic Time

<p>In the past decade, Galactic Chemical Evolution (GCE) has flourished due to surveys like Gaia, LAMOST, and Galex, which have enabled detailed investigations of stellar abundances. Stellar nucleosynthesis has also made strides in calculating both stable and radioactive isotopes, including the heavy isotopes produced by rapid neutron-capture (r-process). However, the astrophysical sources of r-p...</p>

2023.04.28

Alternative theories of gravity and their tests using astronomy observations

<p>General relativity is currently the standard theory to describe gravity. It has passed all the tests in our Solar System and has been positively supported by astronomy observations including electromagnetic waves from neutron stars and gravitational waves from coalescing compact binary systems. But fundamentally it is incompatible with quantum theory, and there are also the large-scale observat...</p>

2023.04.21

A fast radio burst source at a complex magnetized site in a barred galaxy

<p>Fast radio bursts (FRBs) are highly dispersed, millisecond-duration radio bursts prevailing in the universe. Recent observations of a Galactic FRB suggest that at least some FRBs originate from magnetars, but it is unclear whether the majority of cosmological FRBs, especially the actively repeating ones, are produced from the magnetar channel. Until now, more than 800 FRBs have been detected by...</p>