MKN 421 : X-ray and optical outburst
H.G. Boerst et al. reported; following the detection of enhanced
X-ray emission from the BL Lac object Markarian 421 with the RXTE/ASM,
observations with the Cherenkov telescopes show very strong TeV
activity. Above a threshold energy of 500 GeV, daily integrated fluxes
(20 minute averages) reach up to 1, 4, 2, 1.5, 2.5, and 3 times the
TeV flux of the Crab Nebula in consecutive nights during January 16-22.
The ASM observations of Mkn 421 in mCrab at 2-12 keV: 44(2) over UT 2001
January 13-18; 30(3) Jan 19-20; 54(3) on Jan 21, and 80(6) on Jan 22.
The peak is the brightest X-ray flux seen from a BL Lac object during
the RXTE Mission
(vsnet-campaign-blazar 128).
No exceedingly brightening at optical range has been observed to VSNET
(vsnet-campaign-blazar 133,
137),
but observations on January 28 indicate a possible one
(vsnet-campaign-blazar 139).
The confirmed optical outburst of 12.6mag was detected on February
18 reported by M. Simonsen
(vsnet-campaign-blazar 147).
During this outburst, L. Takalo reported that Mrk 421 has brightened
quite a lot at TeV- energies, showing also very rapid variability
(vsnet-campaign-blazar 157).
A very bright magnitude of 12.3mag was reported on March 18
(vsnet-campaign-blazar 167).
In the early May, the object experienced a temporary slight fading
(vsnet-campaign-blazar 193),
The next week, the object recovered to the bright state
(vsnet-campaign-blazar 196).
Other related articles:
vsnet-campaign-blazar 129,
vsnet-campaign-blazar 130,
134,
151,
153,
154,
155,
158,
161,
163,
164,
165,
166,
170,
171,
174,
178,
184,
vsnet-campaign-xray 60,
vsnet-campaign-nova 260
Links:
Comparison stars for observations [
vsnet-campaign-blazar 131]
Sequence presented by B. Skiff [
vsnet-campaign-blazar 132]