The BeppoSAX Calendar 1999

January 

Sun Mon Tue Wed Thu Fri Sat
                     1   2
 3   4   5   6   7   8   9
10  11  12  13  14  15  16
17  18  19  20  21  22  23
24  25  26  27  28  29  30
31

The image mosaic to the left has been constructed using data from the BeppoSAX X-ray telescopes (LECS and MECS). It shows several X-ray pulsars found in the nearby galaxy known as the Small Magellanic Cloud. The power spectrum and folded lightcurve shown on the right side refer to the recently discovered pulsar 1SAX J0103.2-7209. Courtesy of G. Israel, Oss. Astr. di Roma-Monteporzio, Italy.


February 
Sun Mon Tue Wed Thu Fri Sat
     1   2   3   4   5   6
 7   8   9  10  11  12  13
14  15  16  17  18  19  20
21  22  23  24  25  26  27
28

These pictures show the discovery observation of the X-ray afterglow from the famous Gamma Ray Burst GRB970228 together with a follow-up observation carried out three days after the event. By the time of the second observation the X-ray afterglow dimmed below the BeppoSAX detectability threshold. The plot to the right shows the rapid decay of the X-ray flux coming from a different Gamma Ray Burst event which occurred on May 8 1997. The X-ray intensity from this source decreased almost one million times in less than one week. Courtesy of the BeppoSAX Team, and L. Piro, IAS, CNR, Rome
March 

Sun Mon Tue Wed Thu Fri Sat
     1   2   3   4   5   6
 7   8   9  10  11  12  13
14  15  16  17  18  19  20
21  22  23  24  25  26  27
28  29  30  31

The BeppoSAX observation of eight binary pulsars led to the detection of cyclotron lines in six of them. In three cases (the 4.8 sec high-mass X-ray pulsar Cen X-3; the 7.7 sec low-mass X-ray binary pulsar 4U1626-67; and the 700 sec high-mass X-ray pulsar GX301-2) such features were never observed before. The broad-band spectrum of 4U1626-67 is shown on the left side. The figure on the right shows the spectra of the eight pulsars divided by the spectrum of the Crab Nebula, a technique that is used to visualize spectral features such as cycrotron lines. Courtesy of M. Orlandini and D. Dal Fiume, TeSRE Institute, CNR, Bologna, Italy.


April 
Sun Mon Tue Wed Thu Fri Sat
                 1   2   3
 4   5   6   7   8   9  10
11  12  13  14  15  16  17
18  19  20  21  22  23  24
25  26  27  28  29  30

BeppoSAX broad-band X-Ray spectra of two Active Galactic Nuclei: the Quasar 3C273 and the Seyfert type 2 galaxy MKN 3. The spectral distibutions are similar above approximately 10 keV (PDS data) but very different at lower energies where intervening materials in MKN 3 absorbe most of the soft X-rays. Courtesy of M. Cappi, L. Bassani, TeSRE Institute, CNR, Bologna, Italy. Strongly different spectra such as those of 3C273 and MKN 3 can simply be the result of different source orientations as predicted by the "Unified Schemes of AGN". The diagram on the right side, adapted from Urry and Padovani, shows the basic assumptions of this theory. Courtesy of M. Polletta, ITESRE/CNR, Bologna, Italy May 
Sun Mon Tue Wed Thu Fri Sat
                         1
 2   3   4   5   6   7   8
 9  10  11  12  13  14  15
16  17  18  19  20  21  22
23  24  25  26  27  28  29
30  31

Hard X-ray BeppoSAX observation of the "Lockman hole", the site of the most sensitive survey carried out so far in the soft X-ray band. The image to the left is the background subtracted ~130,000 seconds MECS observation showing a number of hard X-ray sources. On the right side the iso-intensity contours of the BeppoSAX 2-10 keV sources are superposed to the ROSAT HRI ultra-deep (> 1,100,000 seconds) soft X-ray image of the same region. Courtesy of J. Truemper, MPE Garching, G. Hasinger, AIP Potsdam, and P. Giommi, BeppoSAX SDC
June 

Sun Mon Tue Wed Thu Fri Sat
         1   2   3   4   5
 6   7   8   9  10  11  12
13  14  15  16  17  18  19
20  21  22  23  24  25  26
27  28  29  30

Wide-band X-ray spectrum and 2-10 keV lightcurve of AB Doradus and Algol, a rapidly rotating young star and an eclipsing binary system. Large flare events, followed for their entire duration, were detected in both cases. These observations show for the first time that hard X-ray emission (>20 keV) is produced during stellar flares. Courtesy of R. Pallavicini, Palermo Observatory, G. Tagliaferri Brera-Merate Observatory, F. Favata, Space Science Department of ESA and J. Schmitt, University of Hamburg, Germany
July 
Sun Mon Tue Wed Thu Fri Sat
                 1   2   3
 4   5   6   7   8   9  10
11  12  13  14  15  16  17
18  19  20  21  22  23  24
25  26  27  28  29  30  31

Intensity plot and (5.9-7.3 keV) X-ray image of Cas A, the youngest supernova remnant in our galaxy. The regions of high emission apparent in these images, taken at the beginning of the BeppoSAX mission, during the Science Verification Phase, are due to spectral lines from the Fe K complex. Courtesy of M.C. Maccarone, IFCAI/CNR, Palermo, Italy


 August 
Sun Mon Tue Wed Thu Fri Sat
 1   2   3   4   5   6   7
 8   9  10  11  12  13  14
15  16  17  18  19  20  21
22  23  24  25  26  27  28
29  30  31

BeppoSAX monitored the BL Lacertae object MKN 501 during a very high intensity state. These observations revealed spectacular luminosity and spectral variability (right panel) associated with simultaneous emission at extremely high energy (TeV band). MKN501 is one of only three extragalactic sources detected at TeV frequencies. Courtesy of E. Pian, TeSRE Institute, CNR, Bologna, Italy
September 

Sun Mon Tue Wed Thu Fri Sat
             1   2   3   4
 5   6   7   8   9  10  11
12  13  14  15  16  17  18
19  20  21  22  23  24  25
26  27  28  29  30

Left: Mosaic of BeppoSAX MECS images of the central region of our Galaxy in the 2-10 keV energy range. Several bright compact sources, consisting of neutron stars and black holes accreting in binary systems, are concentrated in this region of the Galaxy. Courtesy of S.Mereghetti and L.Sidoli, Istituto di Fisica Cosmica "G.Occhialini", CNR, Milano, Italy. Right: BeppoSAX Wide Field Camera image of the Galactic plane region. A constellation of X-ray binary sources within the very large field of view (only partly shown) of this coded mask instrument trace the Galactic plane. Courtesy of L. Natalucci, IAS/CNR, Rome, Italy, J. Schuurmans, SRON, Utrecht, The Netherlands and J. M. Muller, BeppoSAX SDC Rome, Italy. October 

Sun Mon Tue Wed Thu Fri Sat
                     1   2
 3   4   5   6   7   8   9
10  11  12  13  14  15  16
17  18  19  20  21  22  23
24  25  26  27  28  29  30
31

These BeppoSAX MECS images and the plot to the right show the luminosity evolution of the Soft X-ray Transient Aql X-1, a binary system including a neutron star and a "normal" K star. The detection of Aql X-1 in outburst by the RXTE satellite (green points) triggered a series of BeppoSAX observations (red points) which allowed the investigators for the first time to follow the X-ray emission evolution down to a quiescence phase. Courtesy of S. Campana, Brera Observatory, Milano-Merate
November 

Sun Mon Tue Wed Thu Fri Sat
     1   2   3   4   5   6
 7   8   9  10  11  12  13
14  15  16  17  18  19  20
21  22  23  24  25  26  27
28  29  30

The BeppoSAX LECS+MECS best fit spectrum of the Circinus Galaxy (plot to the left) shows a flat continuum and very strong iron emission. The extrapolation of this 0.1-10 keV spectrum to higher energies (PDS data) shows a further component, likely due to nuclear radiation transmitted trough a thick (~4x1024 cm-2) absorber. Independent evidence of this absorber is shown on the right image taken in the near infrared (H-K color): the yellow-white lane is thought to trace a dusty-gaseous bar that drives gas into the nuclear region causing the absorption inferred from the X-rays. Courtesy of G Matt, III University, Rome, Italyand R. Maiolino, Arcetri Observatory, Florence, Italy
December 
Sun Mon Tue Wed Thu Fri Sat
             1   2   3   4
 5   6   7   8   9  10  11
12  13  14  15  16  17  18
19  20  21  22  23  24  25
26  27  28  29  30  31

The left picture shows the deconvolved photon spectra of the black hole/neutron star X-ray transient XTE J0421+560 during two BeppoSAX TOO observations. The model includes two bremsstrahlung components plus emission lines of O, Ne/Fe-L, Si, S, Ca and Fe-K. The bottom part shows the data to model ratios. The X-ray images in different energy bands shown on the right side have been collected with the LECS instrument. Courtesy of A. Parmar, Space Science Department of ESA and F. Frontera, University of Ferrara, Italy.

Prepared by the
BeppoSAX Science Data Center


Equatorial Aitoff projection of all Gamma Ray Bursts observed by BeppoSAX in 1997-1998. Yellow symbols represent Wide Field Camera detections; red symbols indicate the positive detection of an X-ray afterglow by the BeppoSAX X-ray imaging telescopes. Detection of the afterglow at optical or radio wavelenghts is also reported when available. Courtesy of the BeppoSAX SOC team, Telespazio, Rome, Italy.
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