NICER follow-up observations of the flaring blazar BL Lacertae
ATel #14342; Filippo D'Ammando (INAF-IRA Bologna)
on 22 Jan 2021; 17:52 UT
Credential Certification: Filippo D'Ammando (dammando@ira.inaf.it)
Subjects: X-ray, AGN, Black Hole, Blazar, Quasar
Referred to by ATel #: 14350
Following the recent optical and gamma-ray flaring activity of the blazar BL Lacertae (ATel #14318, #14328, #14330, #14334), the source has been observed by NICER for a DDT request (PI: D'Ammando) between 2021 January 18 20:22 UTC and January 22 11:13 UTC for an effective time of 61.9 ks.
The source is detected above the background across the energy interval 0.3-5.0 keV in the quick look data, with an average count rate of 22.2 counts/s, a factor of 6 higher than the average count rate observed by NICER on 2020 October 11-12 during a previous flaring activity of BL Lacertae (ATel #14096). Variations of the count rate up to a factor of 7 has been observed across the observation, with possible short flares.
Preliminary analysis shows that the NICER spectrum collected over the entire period in the 0.3-5 keV energy range is described by a power-law with a photon index of 2.56 +/- 0.01.
Further NICER observations are planned in the next days and multi-wavelength observations are encouraged.
We thank the NICER PI, Keith Gendreau, and the operation team for the rapid approval and execution of the DDT request. NICER is a 0.2-12 keV X-ray telescope operating on the International Space Station. The NICER mission and portions of the NICER science team activities are funded by NASA.
