相关论文: Variability of EGRET Gamma-Ray Sources

As part of an effort to associate the unidentified EGRET gamma-ray sources with pulsars, error boxes for 19 sources were searched using Arecibo at 327-MHz. The sources were chosen to be out-of-plane and possibly associated with the Gould…

A subset of the unidentified EGRET gamma-ray sources with no active galactic nucleus or other conspicuous counterpart appears to be concentrated at medium latitudes. Their long-term variability and their spatial distribution indicate that…

We have conducted a multiwavelength study of several radio sources within or near the error boxes of EGRET unidentified sources at mid to high Galactic latitude, under the hypothesis that the radio sources are blazars and are thus the best…

Diffuse Galactic gamma-ray emission is produced in interactions of cosmic rays with gas and ambient photon fields and thus provides us with an indirect measurement of cosmic rays in various locations in the Galaxy. The diffuse gamma-ray…

Most counterparts of the identified low-latitude gamma-ray sources are Isolated Neutron Stars (INSs). They are characterized by an extremely high value of the X/optical flux ratio, therefore a systematic X-ray/optical coverage of the fields…

The Fermi All-sky Variability Analysis (FAVA) provides a photometric alternative for identifying week-long gamma-ray flares across the entire sky while being independent of any diffuse Galactic or isotropic emission model. We reviewed 779…

The majority of Galactic high-energy gamma-ray sources continue to elude identification. Currently, we have a handful of firm pulsar identifications, one of which is radio quiet, and a few marginal detections, including one millisecond…

We present the results of radio searches for pulsars within unidentified EGRET source error boxes. Using the Parkes multibeam system, we have surveyed 56 sources at Galactic latitudes |b| > 5 deg which do not appear to be associated with…

We present a variability study of a sample of bright gamma-ray (30 MeV -- 50 GeV) sources. This sample is an extension of the first AGILE catalogue of gamma-ray sources (1AGL), obtained using the complete set of AGILE observations in…

Multi-wavelength studies at radio, infrared, optical, X-ray, and TeV wavelengths have discovered probable counterparts to many Galactic sources of GeV emission detected by EGRET. These include pulsar wind nebulae, high mass X-ray binaries,…

Using the EGRET data and an improved point source analysis, including an energy dependent point spread function and an unbinned maximum likelihood technique, we have been able to place considerably lower limits on the gamma ray flux from…

Measurements of the diffuse extragalactic gamma-ray background (EGRB) are complicated by a strong Galactic foreground. Estimates of the EGRB flux and spectrum, obtained by modeling the Galactic emission, have produced a variety of…

We present X-ray and radio studies of sources which are brightabove 1 GeV (F_{>1GeV} > 4e-8 ph/cm^2/s. Only 11 out of ~30 of these gamma-ray sources have been identified with lower energy counterparts: 5 blazars and 6 pulsars. Three of…

The BATSE experiment has now observed more than 1100 gamma-ray bursts. The observed angular distribution is isotropic, while the brightness distribution of bursts shows a reduced number of faint events. These observations favor a…

In current theoretical models of the blazar subclass of active galaxies, the broadband emission consists of two components: a low-frequency synchrotron component with a peak in the IR to X-ray band, and a high-frequency inverse Compton…

Aims: During the Spectrum Roentgen Gamma (SRG)/ eROSITA all-sky surveys, X-ray sources close to the South Ecliptic Pole (SEP) are observed almost every 4 hours. We aim to identify the sources exhibiting the most significant long-term X-ray…

Optical observations of a sample of 12 $\gamma$-ray bright blazars from four optical data archives, AAVSO, SMARTS, Catalina, and Steward Observatory, are compiled to create densely sampled light curves spanning more than a decade. As a part…

The spectral shape of the unresolved emission from different classes of gamma-ray emitters can be used to disentangle the contributions from these populations to the extragalactic gamma-ray background (EGRB). We present a calculation of the…

We present preliminary results of a statistical analysis obtained with a sample of blazars observed at the Perugia Astronomical Observatory since 1992. We briefly show how these statistical results can be useful to discriminate faint…

We study several properties of blazars detected in the gamma-ray energy range by comparing the EGRET sources with a sample of radio blazars which can be considered possible gamma-ray candidates. We define three classes: non-gamma-ray…