1999/11/10 by F. Haberl, Haberl, F., W. Pietsch +3
Engineering · Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics (astro-ph) #FOS: Physical sciences #Geophysics and Sensor Technology #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9911159
5 pages, LaTex, 5 figures, Accepted for publication in A&A Letters
arxiv created 1999/11/10 · openalex publication_date 1999/11/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We report the discovery of a new isolated neutron star candidate, RX J0420.0-5022, showing evidence (4 sigma) for 22.7 s X-ray pulsations in ROSAT data. NTT observations of the field around the soft X-ray source do not reveal any likely optical counterpart brighter than B = 25.25 implying an X-ray to optical flux ratio of >103.3 and ruling out other possible kinds of X-ray emitters. The X-ray spectrum of RX J0420.0-5022 can be described with blackbody emission with temperature kT of about 57 eV and four ROSAT detections are consistent with no flux variations on time scales of years. The X-ray pulsations, if confirmed, make RX J0420.0-5022 the second long-period isolated neutron star candidate after RX J0720.4-3125. As for this latter source similar conclusions about the magnetic field strength of the neutron star can be drawn depending on evolutionary scenarios.