UNVEILING THE ORIGIN OF GRB 090709A: LACK OF PERIODICITY IN A REDDENED COSMOLOGICAL LONG-DURATION GAMMA-RAY BURST

Journal Article · Thu Jul 15 00:00:00 EDT 2010 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/140/1/224· OSTI ID:21443291

Cenko, S B; Butler, N R; Perley, D A; Morgan, A N; Bloom, J S; Filippenko, A V; Klein, C R; Miller, A A; Starr, D L ^[1]; Ofek, E O; Kulkarni, S R ^[2]; Frail, D A ^[3]; Gorosabel, J; Castro-Tirado, A J ^[4]; Cepa, J ^[5]; Chandra, P ^[6]; De Ugarte Postigo, A ^[7]; Nugent, P E ^[8]

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1. Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)
2. Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States)
3. National Radio Astronomy Observatory, 1003 Lopezville Road, Socorro, NM 87801 (United States)
4. Instituto de Astrofisica de AndalucIa (IAA-CSIC), Apartado de Correos, 3.004, E-18.080 Granada (Spain)
5. Instituto de Astrofisica de Canarias, 38205 La Laguna (Spain)
6. Department of Physics, Royal Military College of Canada, Kingston, ON (Canada)
7. INAF/Osservatorio Astronomico di Brera, via Bianchi 46, 23807 Merate, LC (Italy)
8. Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

We present broadband (gamma-ray, X-ray, near-infrared, optical, and radio) observations of the Swift gamma-ray burst (GRB) 090709A and its afterglow in an effort to ascertain the origin of this high-energy transient. Previous analyses suggested that GRB 090709A exhibited quasi-periodic oscillations with a period of 8.06 s, a trait unknown in long-duration GRBs but typical of flares from soft gamma-ray repeaters. When properly accounting for the underlying shape of the power-density spectrum of GRB 090709A, we find no conclusive (>3{sigma}) evidence for the reported periodicity. In conjunction with the location of the transient (far from the Galactic plane and absent any nearby host galaxy in the local universe) and the evidence for extinction in excess of the Galactic value, we consider a magnetar origin relatively unlikely. A long-duration GRB, however, can account for the majority of the observed properties of this source. GRB 090709A is distinguished from other long-duration GRBs primarily by the large amount of obscuration from its host galaxy (A{sub K,obs} {approx}> 2 mag).

• OSTI ID: 21443291
• Journal Information: Astronomical Journal (New York, N.Y. Online), Vol. 140, Issue 1; Other Information: DOI: 10.1088/0004-6256/140/1/224; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
AFTERGLOW
COSMIC GAMMA BURSTS
GALAXIES
GAMMA RADIATION
NEAR INFRARED RADIATION
NEUTRONS
OSCILLATIONS
PERIODICITY
POWER DENSITY
SPECTRA
STARS
UNIVERSE
X RADIATION
BARYONS
COSMIC RADIATION
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
FERMIONS
HADRONS
INFRARED RADIATION
IONIZING RADIATIONS
NUCLEONS
PRIMARY COSMIC RADIATION
RADIATIONS
VARIATIONS