NOAO >   Observing Info >   Approved Programs >   2013A-0146

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Proposal Information for 2013A-0146


PI: K. L. Li, National Tsing Hua University, lilirayhk@gmail.com
Address: Institute of Astronomy, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan

CoI: H. F. Yu, The University of Hong Kong
CoI: Albert Kong, National Tsing Hua University
CoI: P.H.T. Tam, National Tsing Hua University

Title: Measurement of redshift from a Blazar Candidate TXS 1530-131

Abstract: Several (gamma)-ray flares have been detected from a flat spectrum radio source TXS 1530-131 by the Fermi/LAT in the period between 17-6- 2011 and 7-9-2011. The average photon flux above 100 MeV is ~10^- 6 \mathrmph cm^-2 s^-1 during the above period. No significant (gamma)-ray signal was ever detected before these flares which indicates that the source is at least a factor of %added 100 brighter in (gamma)-rays %added during the flaring state, compared to its quiescent state. Hence the flares could be among the biggest ever observed from a blazar. Pan-STARRS (PS1) data shows that the optical intensity increased by a factor ~50 during the (gamma)-ray %outburst flaring period over its quiescent one. A 3 ks Swift/XRT observation taken on 31-8-2011 indicates that the X-ray flux of this source was ~10^-12 \mathrmerg cm^-2 s^-1. %(this following sentence is pretty vague, and maybe we don't need it) By comparing the observing results with other blazars, we concluded it could be a blazar from long distance. Unfortunately, %since no redshift information of this source is available in the literature, %or from any observation, so we can't estimate the monochromatic luminosity properly. Besides, the lack of redshift knowledge prevents us from constraining the bolometric power and extragalactic background light (EBL) absorption in very high-energy γ-rays. Both are crucial to build a decent model of this object.


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