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Title: IS CALVERA A GAMMA-RAY PULSAR?

Abstract

Originally selected as a neutron star (NS) candidate in the ROSAT All-Sky Survey, 1RXS J141256.0+792204 ('Calvera') was discovered to be a 59 ms X-ray pulsar in a pair of XMM-Newton observations by Zane et al. Surprisingly, their claimed detection of this pulsar in Fermi {gamma}-ray data requires no period derivative, severely restricting its dipole magnetic field strength, spin-down luminosity, and distance to small values. This implies that the cooling age of Calvera is much younger than its characteristic spin-down age. If so, it could be a mildly recycled pulsar, or the first 'orphaned' central compact object (CCO). Here we show that the published Fermi ephemeris fails to align the pulse phases of the two X-ray observations with each other, which indicates that the Fermi detection is almost certainly spurious. Analysis of additional Fermi data also does not confirm the {gamma}-ray detection. This leaves the spin-down rate of Calvera less constrained, and its place among the families of NSs uncertain. It could still be either an ordinary pulsar, a mildly recycled pulsar, or an orphaned CCO.

Authors:
 [1]
  1. Astronomy Department, Columbia University, 550 West 120th Street, New York, NY 10027-6601 (United States)
Publication Date:
OSTI Identifier:
21562540
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 736; Journal Issue: 1; Other Information: DOI: 10.1088/2041-8205/736/1/L3; Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; GAMMA DETECTION; GAMMA RADIATION; PULSARS; COSMIC RADIO SOURCES; DETECTION; ELECTROMAGNETIC RADIATION; IONIZING RADIATIONS; RADIATION DETECTION; RADIATIONS

Citation Formats

Halpern, J. P., E-mail: jules@astro.columbia.edu. IS CALVERA A GAMMA-RAY PULSAR?. United States: N. p., 2011. Web. doi:10.1088/2041-8205/736/1/L3.
Halpern, J. P., E-mail: jules@astro.columbia.edu. IS CALVERA A GAMMA-RAY PULSAR?. United States. doi:10.1088/2041-8205/736/1/L3.
Halpern, J. P., E-mail: jules@astro.columbia.edu. Wed . "IS CALVERA A GAMMA-RAY PULSAR?". United States. doi:10.1088/2041-8205/736/1/L3.
@article{osti_21562540,
title = {IS CALVERA A GAMMA-RAY PULSAR?},
author = {Halpern, J. P., E-mail: jules@astro.columbia.edu},
abstractNote = {Originally selected as a neutron star (NS) candidate in the ROSAT All-Sky Survey, 1RXS J141256.0+792204 ('Calvera') was discovered to be a 59 ms X-ray pulsar in a pair of XMM-Newton observations by Zane et al. Surprisingly, their claimed detection of this pulsar in Fermi {gamma}-ray data requires no period derivative, severely restricting its dipole magnetic field strength, spin-down luminosity, and distance to small values. This implies that the cooling age of Calvera is much younger than its characteristic spin-down age. If so, it could be a mildly recycled pulsar, or the first 'orphaned' central compact object (CCO). Here we show that the published Fermi ephemeris fails to align the pulse phases of the two X-ray observations with each other, which indicates that the Fermi detection is almost certainly spurious. Analysis of additional Fermi data also does not confirm the {gamma}-ray detection. This leaves the spin-down rate of Calvera less constrained, and its place among the families of NSs uncertain. It could still be either an ordinary pulsar, a mildly recycled pulsar, or an orphaned CCO.},
doi = {10.1088/2041-8205/736/1/L3},
journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 1,
volume = 736,
place = {United States},
year = {2011},
month = {7}
}