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  每周简讯
 
08/05/2017-12/05/2017

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

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