相关论文: Optical polarization observations with the MASTER …
As a characteristic feature of generic blazars the polarization behavior of the quasi-periodic optical outbursts observed in OJ287 is investigated. The optical light-curves of the December/2015 outburst are also simulated in terms of the…
Both observations and theoretical models suggest that the emissions in gamma-ray bursts (GRBs) and the afterglows are beamed. We argue that the recent polarization measured in the afterglows gives further evidence of beaming in GRBs. In…
We have observed 79 supernova remnants (SNRs) with the Urumqi 25m telescope at 6cm during the Sino-German 6cm polarization survey of the Galactic plane. We measured flux densities of SNRs at 6cm, some of which are the first ever measured or…
The Fermi gamma-ray space telescope has revolutionized our view of the gamma-ray sky and the high energy processes in the Universe. While the number of known gamma-ray emitters has increased by orders of magnitude since the launch of Fermi,…
We show that the recent measurements of linear polarization in gamma rays from GRB 930131 and GRB 960924 constrain certain types of relativity violations in photons to less than parts in 10^{37}, representing an improvement in sensitivity…
It has been observed that photons in the prompt emission of some gamma-ray bursts (GRBs) are highly polarized. The high polarization is used by some authors to give a strict constraint on the Lorentz invariance violation (LIV). If the…
Evidence of polarized $\gamma$-ray emission ($>$ 50 keV) from Gamma-Ray Bursts (GRBs) has been accumulated in recent years. Measurements have been reported with levels in the range of 30-80\%, typically with limited statistical…
Blazars dominate the extragalactic $\gamma$-ray sky and show pronounced flares. Using public Fermi-LAT light curves for 732 blazars with secure redshifts, I implement an automated pipeline to identify and characterize $\gamma$-ray bursts…
We present six epochs of optical spectropolarimetry of the Type II supernova (SN) 2023ixf ranging from $\sim$ 2 to 15 days after the explosion. Polarimetry was obtained with the Kast double spectrograph on the Shane 3 m telescope at Lick…
Blazars are astrophysical sources whose emission is dominated by non-thermal processes, typically interpreted as synchrotron and inverse Compton emission. Although the general picture is rather robust and consistent with observations, many…
Highly luminous rapid flares are characteristic of processes around compact objects like white dwarfs, neutron stars or black holes. In the high energy regime of X- and gamma-rays, outbursts with variability time-scales of seconds and…
Recently, several eclipsing millisecond pulsars have been shown to experience strong and apparent weak lensing from the outflow of their ionized companions. Lensing can be a powerful probe of the ionized plasma, with the strongest lenses…
The true nature of the progenitor to GRBs remains elusive; one characteristic that would constrain our understanding of the GRB mechanism considerably is gamma-ray polarimetry measurements of the initial burst flux. We present a method that…
The nature of the jets and the role of magnetic fields in gamma-ray bursts (GRB) remains unclear. In a baryon-dominated jet only weak, tangled fields generated in situ through shocks would be present. In an alternative model, jets are…
Much interest has been generated recently by the ongoing MACHO, EROS and OGLE projects to identify gravitationally lensed stars from the Large Magellanic Cloud and Galactic bulge, and the positive identification of several events (Alcock et…
Polarization measurements of the prompt emission in Gamma-ray Bursts (GRBs) can provide diagnostic information for understanding the nature of the central engine. POLAR is a compact polarimeter dedicated to the polarization measurement of…
We have obtained simultaneous and continuous photo-polarization observations of the blazar BL Lacertae in optical and near-infrared (NIR) bands during a historical outburst from 2020 to 2021. In total, fourteen nights of observations were…
We report polarization measurements in two prompt emissions of gamma-ray bursts, GRB 110301A and GRB 110721A, observed with the Gamma-ray burst polarimeter (GAP) aboard IKAROS solar sail mission. We detected linear polarization signals from…
We at first introduce a novel photometric system, which consists of a Schmidt telescope, an objective prism, a CCD camera, and, especially, a multi-peak interference filter. The multi-peak interference filter enables light in multi…
CMB experiments aiming at a precise measurement of the CMB polarization, such as the Planck satellite, need a strong polarized absolute calibrator on the sky to accurately set the detectors polarization angle and the cross-polarization…