SHAO Astrophysics Colloquia
Talk delivered in Chinese, with slides in English
Title: Testing Fundamental Physics With Fast Radio Bursts
Speaker: Xuefeng Wu (PMO)
Time: 3 PM, May 12th (Thursday)
Abstract:
The Einstein's weak equivalence principle (WEP) is one of the foundations of general relativity and many other metric theories of gravity. At the post-Newtonian level, the accuracy of the WEP can be tested through the numerical values of the parametrized post-Newtonian (PPN) parameters, such as the parameter γ. Specifically, the WEP accuracy/violation can be constrained by comparing the γ values for different kinds of particles, or for the same kind of particle with different energies, since all gravity theories satisfying the WEP predict the same γ values for different test particles. On the other hand, the question of whether the photon has a finite rest mass is one of the most important and interesting issues in modern physics, as it is closely related to many fundamental questions such as charge conservation and quantization, and so on. Hence, it is need to push the constraints on the photon mass as far as possible. The most direct method of constraining the photon mass is to detect a possible frequency dependence of the speed of light. In this talk, I will show that both the WEP violation and the rest mass of photon can be well constrained using the time delay of photons with different frequencies arising in extragalactic fast radio bursts (FRBs), which is a new type of millisecond radio burst transients attracting wide attention in the recent years.
Group meetings
Black hole Accretion and High-energy Astrophysics /Black Hole Feedback and Cosmic Ray Astrophysics Seminar
Location: 1608
Time: 14:00-16:00, Wednesday(May 10th)
Speaker: Zhaoming Gan
Title: Using collisions of AGN outflows with ICM shocks as dynamical probes
http://adsabs.harvard.edu/abs/2017PhPl...24d1402J
Speaker: Defu Bu
Title: Three-dimensional hydrodynamical models of wind and outburst-related accretion in symbiotic systems
http://adsabs.harvard.edu/abs/2017MNRAS.468.3408D
Galactic Dynamics Group Journal Club
Location:1608
Time: Thursday (May 11th)
Title: Milky Way Stellar Halo as Seen by SDSS
Speaker: Sarah bird
Abstract:
Although the Milky Way stellar halo contains much information about our Galaxy's formation and evolution, unlocking these clues is complicated due to the halo's the low number of stars and large volume of space in which they reside. I will discuss the series of papers by Xue, X. X., et al. which uses SDSS/SEGUE to catalog and analyze a large sample of Milky Way blue horizontal branch and K-giant halo stars. These works provide catalogs of halo stars with stellar parameters, distances, and velocities. They characterize the Milky Way stellar halo's density and velocity profile over a large Galactocentric range and provide an estimate for the Milky Way's dark matter mass.
Xue+08 THE MILKY WAY’S CIRCULAR VELOCITY CURVE TO 60 kpc AND AN ESTIMATE OF THE DARK MATTER HALO MASS FROM THE KINEMATICS OF ~2400 SDSS BLUE HORIZONTAL-BRANCH STARS
Xue+14 THE SEGUE K GIANT SURVEY. II. A CATALOG OF DISTANCE DETERMINATIONS FOR
THE SEGUE K GIANTS IN THE GALACTIC HALO
Xue+15 THE RADIAL PROFILE AND FLATTENING OF THE MILKY WAY’S STELLAR HALO TO 80 kpc FROM THE SEGUE K-GIANT SURVEY
http://adsabs.harvard.edu/abs/2008ApJ...684.1143X
http://adsabs.harvard.edu/abs/2014ApJ...784..170X
http://adsabs.harvard.edu/abs/2015ApJ...809..144X
Visitors
Name: Prof. Paul Wiita
Affiliation: The College of New Jersey, USA
Dates: 19/04/2017-12/05/2017
Host: Prof. Minfeng Gu
Office: 1519