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GCN Circular 31601

ZTF22aaajecp/AT2022cmc: NICER X-ray detection
2022-02-17T04:19:47Z (2 years ago)
Dheeraj R. Pasham at Mass. Inst. of Technology <>
Dheeraj Pasham (MIT), Keith Gendreau (NASA/GSFC), Zaven Arzoumanian

NICER observed the rapidly fading red transient AT2022cmc for 640 seconds
starting at 2022-02-16T19:07:03. X-rays are clearly detected above the
background in the 0.3-6.0 keV band with a mean count rate of 12.9+-0.14
counts/seconds. We fit the 0.3-6 keV X-ray spectrum with a powerlaw
modified by neutral absorption (tbabs*pow in XSPEC). This gives a good fit
with a chi-squared/degrees of freedom of 216/207. The best-fit power law
index and column density values are 1.56+-0.05 and (3.9+-0.7)e21 cm^-2,
respectively. The 0.3-6 keV observed flux is (3.04+-0.05)e-11 erg/s/cm^2.

Further NICER observations are planned. To coordinate NICER/X-ray
observations with other facilities please contact

NICER can carry out prompt follow-up observations of transients and is
planning to systematically follow up alerts from LIGO/Virgo and other X-ray
bright extra-galactic transients in the future.

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.

Dheeraj Pasham
Research Scientist, MIT
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