Results on timing and spectral properties of the Be/X-ray binary pulsar 3A 0726-260(4U 0728-25)are presented.The binary was observed on 2016 May 6-7 with the Large Area X-ray Proportional Counter(LAXPC)and Soft X-ray ...Results on timing and spectral properties of the Be/X-ray binary pulsar 3A 0726-260(4U 0728-25)are presented.The binary was observed on 2016 May 6-7 with the Large Area X-ray Proportional Counter(LAXPC)and Soft X-ray Telescope(SXT)instruments onboard the AstroSat satellite.During this observation,the source was in non-flaring persistent state at a flux level of^8.6±0.3×10^-11 erg cm^-2 s^-1in 0.4-20 keV.Strong X-ray pulsations with a period of 103.144±0.001 s are detected in 0.3-7 keV with the SXT and in 3-40 keV with the LAXPC.The pulse profile is energy dependent,and there is an indication that the pulse shape changes from a broad single pulse to a double pulse at higher energy.At energies above20 keV,we report the first time detection of pulsation period 103.145±0.001 s and the double peaked pulse profile from the source.The energy spectrum of the source is derived from the combined analysis of the SXT and LAXPC spectral data in 0.4-20 keV.The best spectral fit is obtained by a power law model with a photon index(1.7±0.03)with high energy spectral cut-off at 12.9±0.7 keV.A broad iron line at^6.3 keV is detected in the energy spectrum.We briefly discuss the implications of these results.展开更多
We present evidences showing that the Be star 3G71, proposed as the optical cou- nterpart of the Be / X-ray binary source 1H2214 + 589, may be a Herbig Ae / Be star. These evidences can be summarized as follows. 1. We...We present evidences showing that the Be star 3G71, proposed as the optical cou- nterpart of the Be / X-ray binary source 1H2214 + 589, may be a Herbig Ae / Be star. These evidences can be summarized as follows. 1. We made spectroscopic observations by using a CCD spectrograph with dispersi- ons 50 A / mm and 195 A / mm at the BAO 2.16m telescope. Analysis of the optical spectra of 3G71 indicates: a. Forbidden lines, such as [OI] 6300 and 6363 A, [FeII] 5527, 4889, 4814, 4415, 4359 and 4304 A, are present in the spectra (Fig.2a, Fig.2b). b. The Hα emission line is unusually strong. Its equivalent width is sometimes more than 100 A (Fig. 1). The photospheric absorption lines of hydrogen are very wide. In the case of Hβ, the distance between two wings amounts to 60 A (Fig.2a, Fig.3). 2. We have performed cross-identification between HST GSC catalogue and IRAS Point Source Catalogue and found the IRAS point souree counterpart of 3G71 to be 2248 + 6058. Its equatorial coordinates (at equinox 1950.0) are 22h24m53s.8 and +60°58′ 15″, while those given by the GSC catalogue are 22h24m53s.37 and +60°58′13″.1. The differences are merely 0.4s and 2″, being less than the uncertainty ellipse (major axis: 11″, minor axis: 6″) given in IRAS PSC. Table 1 lists the flux densities quoted from IRAS GSC and the deduced IRAS IR magnitudes. It is clear from the table that 3G71 has a very large IR color excess, since the V magnitude of 3G71 found from GSC is 12.2 and its V-[25]=+12.47, which is much larger than that expected for classical Be stars and satisfies the criterion for the Herbig Ae / Be stars given by Hu et al., i.e., V-[25] > 7. 3. Using Palomar sky survey map, we have made a search for a nebulosity in the immediate vicinity of 3G71 and actually discovered a bright nebula, at whose center 3G71 is just located. Its diameter is about 1 are-minute. It is concluded from the characteristics of 3G71 mentioned above that 3G71 may be a Herbig Ae / Be star.展开更多
The BES-Ⅲ Detector is a very versatile multipurpose device located at the Institute of High Energy Physics （IHEP） in Beijing, China. Concerning the physics program it ties stringently up to the past BES and BES-Ⅱ ...The BES-Ⅲ Detector is a very versatile multipurpose device located at the Institute of High Energy Physics （IHEP） in Beijing, China. Concerning the physics program it ties stringently up to the past BES and BES-Ⅱ experiments. Since start of the data taking in the middle of 2008 the accumulated dataset of 200.10^6 J/ψ events and 100.10^6 ψ＇ events already exceeds the world data on these resonances. In addition to studies of the charmonium systems the data offers great opportunity for investigations in the light hadron sector. In detail it will be reported about the confirmation of the enhancement in pp invariant mass in radiative J/ψ decays, the search for decays Y（2175） → K＊0K＊0, observation of a charged K^± in K^±π^0 and observation of a new excited baryon N＊（2065） decaying to pπ^0 and charged onjugate. The first result is based on data taken by BES-Ⅱ and BES-Ⅲ, the latter three on data collected by BES-Ⅱ only.展开更多
基金ISRO for providing funding supportmade use of softwares obtained through the HEASARC Online Service,provided by NASA/GSFC,in support of NASA High Energy Astrophysics Programs。
文摘Results on timing and spectral properties of the Be/X-ray binary pulsar 3A 0726-260(4U 0728-25)are presented.The binary was observed on 2016 May 6-7 with the Large Area X-ray Proportional Counter(LAXPC)and Soft X-ray Telescope(SXT)instruments onboard the AstroSat satellite.During this observation,the source was in non-flaring persistent state at a flux level of^8.6±0.3×10^-11 erg cm^-2 s^-1in 0.4-20 keV.Strong X-ray pulsations with a period of 103.144±0.001 s are detected in 0.3-7 keV with the SXT and in 3-40 keV with the LAXPC.The pulse profile is energy dependent,and there is an indication that the pulse shape changes from a broad single pulse to a double pulse at higher energy.At energies above20 keV,we report the first time detection of pulsation period 103.145±0.001 s and the double peaked pulse profile from the source.The energy spectrum of the source is derived from the combined analysis of the SXT and LAXPC spectral data in 0.4-20 keV.The best spectral fit is obtained by a power law model with a photon index(1.7±0.03)with high energy spectral cut-off at 12.9±0.7 keV.A broad iron line at^6.3 keV is detected in the energy spectrum.We briefly discuss the implications of these results.
文摘We present evidences showing that the Be star 3G71, proposed as the optical cou- nterpart of the Be / X-ray binary source 1H2214 + 589, may be a Herbig Ae / Be star. These evidences can be summarized as follows. 1. We made spectroscopic observations by using a CCD spectrograph with dispersi- ons 50 A / mm and 195 A / mm at the BAO 2.16m telescope. Analysis of the optical spectra of 3G71 indicates: a. Forbidden lines, such as [OI] 6300 and 6363 A, [FeII] 5527, 4889, 4814, 4415, 4359 and 4304 A, are present in the spectra (Fig.2a, Fig.2b). b. The Hα emission line is unusually strong. Its equivalent width is sometimes more than 100 A (Fig. 1). The photospheric absorption lines of hydrogen are very wide. In the case of Hβ, the distance between two wings amounts to 60 A (Fig.2a, Fig.3). 2. We have performed cross-identification between HST GSC catalogue and IRAS Point Source Catalogue and found the IRAS point souree counterpart of 3G71 to be 2248 + 6058. Its equatorial coordinates (at equinox 1950.0) are 22h24m53s.8 and +60°58′ 15″, while those given by the GSC catalogue are 22h24m53s.37 and +60°58′13″.1. The differences are merely 0.4s and 2″, being less than the uncertainty ellipse (major axis: 11″, minor axis: 6″) given in IRAS PSC. Table 1 lists the flux densities quoted from IRAS GSC and the deduced IRAS IR magnitudes. It is clear from the table that 3G71 has a very large IR color excess, since the V magnitude of 3G71 found from GSC is 12.2 and its V-[25]=+12.47, which is much larger than that expected for classical Be stars and satisfies the criterion for the Herbig Ae / Be stars given by Hu et al., i.e., V-[25] > 7. 3. Using Palomar sky survey map, we have made a search for a nebulosity in the immediate vicinity of 3G71 and actually discovered a bright nebula, at whose center 3G71 is just located. Its diameter is about 1 are-minute. It is concluded from the characteristics of 3G71 mentioned above that 3G71 may be a Herbig Ae / Be star.
文摘The BES-Ⅲ Detector is a very versatile multipurpose device located at the Institute of High Energy Physics （IHEP） in Beijing, China. Concerning the physics program it ties stringently up to the past BES and BES-Ⅱ experiments. Since start of the data taking in the middle of 2008 the accumulated dataset of 200.10^6 J/ψ events and 100.10^6 ψ＇ events already exceeds the world data on these resonances. In addition to studies of the charmonium systems the data offers great opportunity for investigations in the light hadron sector. In detail it will be reported about the confirmation of the enhancement in pp invariant mass in radiative J/ψ decays, the search for decays Y（2175） → K＊0K＊0, observation of a charged K^± in K^±π^0 and observation of a new excited baryon N＊（2065） decaying to pπ^0 and charged onjugate. The first result is based on data taken by BES-Ⅱ and BES-Ⅲ, the latter three on data collected by BES-Ⅱ only.
