NASA Logo, External Link
Facebook icon, External Link to NASA STI page on Facebook Twitter icon, External Link to NASA STI on Twitter YouTube icon, External Link to NASA STI Channel on YouTube RSS icon, External Link to New NASA STI RSS Feed AddThis share icon
 

Record Details

Record 12 of 55453
A Central X-ray Source in the Non-thermal Radio Nebula DA 495
Offline Availability: Go to Request Form
Author and Affiliation:
Arzoumanian, Z.(Universities Space Research Association, Lab. for High Energy Astrophysics, Greenbelt, MD, United States)
Safi-Harb, S.(Manitoba Univ., Dept. of Physics and Astronomy, Winnipeg, Manitoba, Canada)
Landecker, T. L.(Dominion Astrophysical Observatory, Penticton, British Columbia, Canada)
Kothes, R.(Dominion Astrophysical Observatory, Penticton, British Columbia, Canada)
Abstract: We report the detection, in archival ROSAT and ASCA observations, of X-ray emission from the direction of DA 495 (G65.7+1.2), a likely supernova remnant of uncertain classification but with similarities to the Crab Nebula. An unusual feature of the radio nebula is its annular morphology, with a flux minimum at the geometrical center. In the soft X-ray band, the ROSAT data resolve a compact source near the edge of the central radio hole ; the hard X-ray morphology, at the limit of ASCA's spatial resolution, is suggestive of extended plerionic emission dropping off from a central flux maximum coincident with the ROSAT source. The spectrum is well-described by a power-law with photon index approximately 1.7, and the X-ray flux is roughly constant with time. Taken together, this evidence suggests identification of the X-ray source with a magnetospherically active neutron star and its associated wind nebula. Timing analysis of the ASCA data yields only a weak upper bound on pulsations with periods longer than approximately 30 ms. These results reveal for the first time the high-energy engine that powers the synchrotron nebula, and strengthen the classification of DA 495 as a plerionic supernova remnant, one that may represent a late evolutionary stage of Crab-like nebulae.
Publication Date: Jan 01, 2003
Document ID:
20040040115
(Acquired Mar 31, 2004)
Subject Category: ASTRONOMY
Document Type: Preprint
Contract/Grant/Task Num: NRA-99-01-LTSA-070
Financial Sponsor: NASA Goddard Space Flight Center; Greenbelt, MD, United States
Natural Sciences and Engineering Research Council; Ottawa, Ontario, Canada
Organization Source: Universities Space Research Association; Lab. for High Energy Astrophysics; Greenbelt, MD, United States
Description: 5p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: No Copyright
NASA Terms: CRAB NEBULA; X RAY SOURCES; RADIO ASTRONOMY; ASTROPHYSICS; SUPERNOVA REMNANTS; DETECTION; NEUTRON STARS; INTERSTELLAR MATTER; SYNCHROTRONS; ROSAT MISSION; IMAGE ANALYSIS; SIGNAL TO NOISE RATIOS
› Back to Top
Find Similar Records
NASA Logo, External Link
NASA Official: Gerald Steeman
Site Curator: STI Program
Last Modified: September 08, 2011
Contact Us