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GCN Circular 21964

Subject
LIGO/Virgo G299232: MAGIC Cherenkov Telescopes observations
Date
2017-10-03T13:25:13Z (7 years ago)
From
Antonio Stamerra at INAF-OATo/SNS-Pisa <antonio.stamerra@sns.it>
R. Mirzoyan on behalf of the MAGIC Collaboration

In response to the LIGO/Virgo GW event G299232 (GCN 21693), the MAGIC Cherenkov Telescopes located at the Observatory El Roque de Los Muchachos of the Istituto de Astrofisica de Canarias (IAC) observed the following targets reported by follow-up observations:

Target-1: the IceCube muon-1 region (GCN 21694 and GCN 21698);
Target-2: the optical transient reported by MASTER OTJ033744.97+723159.0 (GCN 21719, GCN 21720, GCN 21736);
Target-3: Swift-UVOT transient (GCN 21733).

Target-1 
=======

A scan of the region defined by the neutrino-muon detected by IceCube (RA: 28.2 deg DEC: 44.8 deg sigma: 3.8 deg, GCN 21698) was performed through four different pointings on August 26, between 03:03 and 05:28 UT

Pointing-1: RA: +01h 52m 48.0s DEC: +44d 47m 60.0s; Effective observation time: 0.51 hr 
Pointing-2: RA: +01h 46m 24.0s DEC: +44d 47m 60.0s; Effective observation time: 0.57 hr
Pointing-3: RA: +01h 49m 36.0s DEC: +46d 12m 00.0s; Effective observation time: 0.51 hr
Pointing-4: RA: +01h 49m 36.0s DEC: +43d 12m 00.0s; Effective observation time: 0.51 hr

corresponding to a region of ~10 deg^2, RA: ~26-29 deg DEC:~ 43-46 deg. 

Weather conditions were not ideal, with somewhat reduced transmission because of the Sahara dust in the atmosphere.

A preliminary skymap was built. No excess is found. Very preliminary upper limits at E>200 GeV are ~1.5e-11 ph/cm2/s, valid only at the center of the field of view.


Target-2 
=======

MAGIC observed at the position of MASTER OTJ033744.97+723159.0, RA: 03h 37m 44.97s DEC: +72d 31m 59.0s (GCN 21719) on August 28, from 03:24 to 05:26 UT for 1.92 hrs effective time and on August 29, from 01:50 and 03:15 UT for 0.97 hrs effective time.

Fair weather conditions, partially affected by dust and moderate atmospheric absorption.

No significant excess was found. The preliminary upper limit on the flux at E>200 GeV is 5.5e-12 ph/cm2/s. 


Target-3 
=======

MAGIC observed at the position of the unidentified transient detected by Swift/UVOT RA: 01h 40m 08.55s DEC: +34d 34m 03.6s (GCN 21733) on August 29 at 03:23 UT for 0.8 hrs effective time.

Fair weather conditions, partially affected by dust and moderate atmospheric absorption.

No significant excess was found. The preliminary upper limit on the flux at E>200 GeV is 2.1e-11 ph/cm2/s. 

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MAGIC is a system of two 17m-diameter Imaging Atmospheric Cherenkov Telescopes located at the the Observatory El Roque de Los Muchachos of the Istituto de Astrofisica de Canarias (IAC), Spain and designed to perform gamma-ray astronomy in the energy range from 50 GeV to greater than 50 TeV, (https://magic.mpp.mpg.de).
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