Search Publications
Spacecraft Doppler tracking with possible violations of LLI and LPI: upper bounds from one-way measurements on MEX
Xie, Yi; Huang, Yong
We analyze the post-fit residuals of one-way Doppler tracking data from the Mars Express (MEX) spacecraft to test possible violations of local Lorentz invariance (LLI) and local position invariance (LPI). These one-way Doppler observations were carried out on 2011 August 7 for about 20 minutes at Sheshan Station of Shanghai Astronomical Observator…
On the diffuse soft X-ray emission from the nuclear region of M51
Mao, Shu-De; Liu, Ji-Ren
We present an analysis of the diffuse soft X-ray emission from the nuclear region of M51 combining both XMM-Newton RGS and Chandra data. Most of the RGS spectrum of M51 can be fitted with a thermal model with a temperature of ∼ 0.5 keV except for the O VII triplet, which is forbidden-line dominated. The Fe L-shell lines peak around the southern cl…
Ionospheric inversion of the Venus Express radio occultation data observed by Shanghai 25 m and New Norcia 35 m antennas
Zhang, Su-Jun; Jian, Nian-Chuan; Li, Jin-Ling +3 more
Electron density profiles of Venus' ionosphere are inverted from the Venus Express (VEX) one-way open-loop radio occultation experiments carried out by the Shanghai 25 m antenna from November 2011 to January 2012 at solar maximum conditions and by the New Norcia 35 m antenna from August 2006 to June 2008 at solar intermediate conditions. The elect…
Development of technique to detect and classify small-scale magnetic flux cancellation and rapid blue-shifted excursions
Liu, Chang; Jing, Ju; Wang, Haimin +5 more
We present a set of tools for detecting small-scale solar magnetic cancellations and the disk counterpart of type II spicules (the so-called Rapid Blueshifted Excursions (RBEs)), using line-of-sight photospheric magnetograms and chromospheric spectroscopic observations, respectively. For tracking magnetic cancellation, we improve the Southwest Aut…
The local contribution to the microwave background radiation
Pecker, Jean-Claude; Narlikar, Jayant V.; Ochsenbein, Francois +1 more
The observed microwave background radiation (MBR) is commonly interpreted as the relic of an early hot universe, and its observed features (spectrum and anisotropy) are explained in terms of properties of the early universe. Here we describe a complementary, even possibly alternative, interpretation of MBR, first proposed in the early 20th
Propagating disturbances along a coronal loop from simultaneous EUV imaging and spectroscopic observations
Krishna Prasad, S.; Banerjee, Dipankar; Datta, Ajanta
Propagating disturbances (PDs) were studied along an active region loop using simultaneous imaging and spectroscopy. An image sequence recorded in the Fe IX/Fe X 171Å channel, from TRACE and spectral data in the Si XII 520.6 Å line obtained from CDS/SOHO, are analyzed. A space-time map constructed from the TRACE image sequence shows the presence o…
The inner ∼ 40 pc radial distribution of the star formation rate for a nearby Seyfert 2 galaxy M51
Bian, Wei-Hao; He, Zhi-Cheng; Fang, Li-Ling +1 more
We investigate the spatially resolved specific star formation rate (SSFR) in the inner ∼40 pc for a nearby Seyfert 2 galaxy, M51 (NGC 5194) by analyzing spectra obtained with the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS). We present 24 radial spectra measured along the STIS long slit in M51, extending ∼ 1″ from the n…