A dataset provided by the European Space Agency

Name: Long-term phase-connected timing of the unique X-ray binary HD49798
Published: 2021-03-17T00:00:00Z

Proposal ID	084127
Title	Long-term phase-connected timing of the unique X-ray binary HD49798
Download Data Associated to the proposal	https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0841270101
DOI	https://doi.org/10.57780/esa-4ji0578
Principal Investigator, PI	Dr SANDRO MEREGHETTI
Abstract	HD49798 is the only known X-ray binary with a hot subdwarf companion. Thecompact object (a white dwarf or a neutron star) has a spin period of 13 s andhas been steadily spinning up at 2x10^{-15} s/s for the last 20 years.Independently of its NS or WD nature, this spin-up is difficult to explain withthe angular momentum that accretion can supply. An alternative explanationimplies the presence of a young WD, still in the contracting phase. A newobservation must be secured as soon as possible in order to extend the phaseconnected timing solution of this unique binary and shed light on thenature ofthe compact object. This fulfil proposal was accepted in AO17 (C priority) butnot executed.
Publications	New X-ray observations of the hot subdwarf binary HD 49798/RX J0648.0-4418 \|Mereghetti, S., Pintore, F., et al. \| MNRAS \| 504-920 \| 2021 \| 2021MNRAS.504..920M \| http://ui.adsabs.harvard.edu/#abs/2021MNRAS.504..920M Timing the X-ray pulsating companion of the hot subdwarf HD 49798 with NICER \|Rigoselli, Michela, De Grandis, Davide, et al. \| MNRAS \| 523-3043 \| 2023 \| 2023MNRAS.523.3043R \| http://ui.adsabs.harvard.edu/#abs/2023MNRAS.523.3043R The XMM-Newton Line Emission Analysis Program (X-LEAP). I. Emission-line Survey of O VII, O VIII, and Fe L-shell Transitions \|Pan, Zeyang, Qu, Zhijie, et al. \| ApJS \| 271-62 \| 2024 \| 2024ApJS..271...62P \| http://ui.adsabs.harvard.edu/#abs/2024ApJS..271...62P
Instrument	EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage	2020-02-27T06:27:36Z/2020-02-27T19:39:16Z
Version	18.02_20200221_1200
Mission Description	The European Space Agencys (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESAs second cornerstone of the Horizon 2000 Science Programme. It carries 3 high throughput X-ray telescopes with an unprecedented effective area, and an optical monitor, the first flown on a X-ray observatory. The large collecting area and ability to make long uninterrupted exposures provide highly sensitive observations. Since Earths atmosphere blocks out all X-rays, only a telescope in space can detect and study celestial X-ray sources. The XMM-Newton mission is helping scientists to solve a number of cosmic mysteries, ranging from the enigmatic black holes to the origins of the Universe itself. Observing time on XMM-Newton is being made available to the scientific community, applying for observational periods on a competitive basis.
Creator Contact	https://www.cosmos.esa.int/web/xmm-newton/xmm-newton-helpdesk
Date Published	2021-03-17T00:00:00Z
Keywords	"phase connected", "term phase connected", "xray binary", "angular momentum", "shed light", "alternative explanation implies", "neutron star", "steadily spinning", "spin period", "xray binary hd49798", "white dwarf", "compact object", "2x10 ^{", "hot subdwarf companion", "contracting phase"
Publisher And Registrant	European Space Agency
Credit Guidelines	European Space Agency, Dr SANDRO MEREGHETTI, 2021, 'Long-term phase-connected timing of the unique X-ray binary HD49798', 18.02_20200221_1200, European Space Agency, https://doi.org/10.57780/esa-4ji0578