3XMM J004232.1 411314

3XMM J004232.1 411314
Observation data; Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation	Andromeda
Right ascension	00h 42m 32.072s
Declination	41° 13′ 14.33″
Characteristics
Variable type	Low-mass X-ray binary
Database references
SIMBAD	data

3XMM J004232.1 411314 is a low-mass X-ray binary hosted in the galaxy M31. It is the most luminous source of hard X-rays in the Andromeda Galaxy. It is also the most luminous source known that shows dips in the X-ray light curve.^[1] The compact object in this system has been unambiguously identified as a neutron star with a spin period of 3 seconds.^[2]

Identification of the source

The Swift BAT all-sky survey detected hard X-rays (in the energy range 14-195 keV) in the direction of M31 and found that this emission was centered in a region 6 arcseconds away from the galaxy center. Using a subsequent NuSTAR observation, it was found that a single source was responsible for this emission, and optical HST images ruled out the presence of stars more massive than 3 solar masses in that direction.^[3]

The same source was earlier observed in soft X-rays by XMM-Newton, and was given the catalogue name 3XMM J004232.1 411314. By analysing archival data elaborated by the EXTraS project, this source showed dips (a short and linear decrease in the source luminosity, which returns subsequently at the previous luminosity level) in some observations. As this behaviour is typical of X-ray binaries, then this source can be identified as a low-mass X-ray binary.^[1]

System properties

The orbit of this binary system has an inclination between 60° and 80° from our line of sight, since dips are observed only in this inclination range. The orbital period of the system is 4.01 hours, which is the same distance in time between two consecutive dips. ^[1] Like many others low-mass X-ray binaries, the luminosity of this source varies over time. Using XMM-Newton observations of Andromeda Galaxy, this source luminosity stays in the range 0.8–2.8×10³⁸ erg/s in the 0.2-12 keV photon energy band. To date, this is the most luminous source that shows dips in its X-ray lightcurves.^[1]

The compact object of this system is a neutron star with a spin period of 3 seconds, and this is proved by the observation of a modulation with the same period in the X-ray luminosity.^[2]

References

^ ^a ^b ^c ^d ^e ^f ^g Marelli, M.; Tiengo, A.; De Luca, A.; Salvetti, D.; Saronni, L.; Sidoli, L.; Paizis, A.; Salvaterra, R.; Belfiore, A.; Israel, G.; Haberl, F.; D'Agostino, D. (2017), "Discovery of periodic dips in the brightest hard X-ray source of M31 with EXTraS", The Astrophysical Journal Letters, 851 (2): L27, arXiv:1711.05540, Bibcode:2017ApJ...851L..27M, doi:10.3847/2041-8213/aa9b2e, S2CID 119266242
^ ^a ^b Rodríguez Castillo, G.A.; Israel, G.L.; Esposito, P.; Papitto, A.; Stella, L.; Tiengo, A.; De Luca, A.; Marelli, M. (2018), "Discovery of a 3 s Spinning Neutron Star in a 4.15 hr Orbit in the Brightest Hard X-Ray Source in M31", The Astrophysical Journal Letters, 861 (2): L26, arXiv:1804.10858, Bibcode:2018ApJ...861L..26R, doi:10.3847/2041-8213/aacf40, S2CID 119007575
^ Yukita, M.; Ptak, A.; Hornschemeier, A.E.; Wik, D.; Maccarone, J.; Pottschmidt, K.; De Luca, A.; Zezas, A.; Antoniou, V.; Ballhausen, R.; Lehmer, B.D.; Lien, A.; Williams, B.; Baganoff, F.; Boyd, P.T.; Enoto, T.; Kennea, J.; Page, K.L.; Choi, Y. (2017), "Identification of the Hard X-ray Source Dominating the E > 25 keV Emission of the Nearby Galaxy M31", The Astrophysical Journal, 838 (1): 47, arXiv:1703.07318, Bibcode:2017ApJ...838...47Y, doi:10.3847/1538-4357/aa62a3, hdl:1721.1/109690, S2CID 118910239

External links

Example of two consecutive dips in an X-ray light curve of this source^{[permanent dead link‍]} From EXTraS Archive.

[APJL2017-1] ^ ^a ^b ^c ^d ^e ^f ^g Marelli, M.; Tiengo, A.; De Luca, A.; Salvetti, D.; Saronni, L.; Sidoli, L.; Paizis, A.; Salvaterra, R.; Belfiore, A.; Israel, G.; Haberl, F.; D'Agostino, D. (2017), "Discovery of periodic dips in the brightest hard X-ray source of M31 with EXTraS", The Astrophysical Journal Letters, 851 (2): L27, arXiv:1711.05540, Bibcode:2017ApJ...851L..27M, doi:10.3847/2041-8213/aa9b2e, S2CID 119266242

[APJL2018-2] Rodríguez Castillo, G.A.; Israel, G.L.; Esposito, P.; Papitto, A.; Stella, L.; Tiengo, A.; De Luca, A.; Marelli, M. (2018), "Discovery of a 3 s Spinning Neutron Star in a 4.15 hr Orbit in the Brightest Hard X-Ray Source in M31", The Astrophysical Journal Letters, 861 (2): L26, arXiv:1804.10858, Bibcode:2018ApJ...861L..26R, doi:10.3847/2041-8213/aacf40, S2CID 119007575

[Yukita2017-3] Yukita, M.; Ptak, A.; Hornschemeier, A.E.; Wik, D.; Maccarone, J.; Pottschmidt, K.; De Luca, A.; Zezas, A.; Antoniou, V.; Ballhausen, R.; Lehmer, B.D.; Lien, A.; Williams, B.; Baganoff, F.; Boyd, P.T.; Enoto, T.; Kennea, J.; Page, K.L.; Choi, Y. (2017), "Identification of the Hard X-ray Source Dominating the E > 25 keV Emission of the Nearby Galaxy M31", The Astrophysical Journal, 838 (1): 47, arXiv:1703.07318, Bibcode:2017ApJ...838...47Y, doi:10.3847/1538-4357/aa62a3, hdl:1721.1/109690, S2CID 118910239

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[2]

[3]

v t e Andromeda Galaxy
Location	Andromeda Galaxy → Andromeda subgroup → Local Group → Local Sheet → Virgo Supercluster → Laniakea Supercluster → Local Hole → Observable universe → Universe Each → may be read as "within" or "part of".	Andromeda Galaxy
Satellite galaxies	M32 M110 NGC 185 NGC 147 Andromeda I Andromeda II Andromeda III Andromeda IV* Andromeda V Andromeda VI Andromeda VII Andromeda VIII Andromeda IX Andromeda X Andromeda XI Andromeda XII Andromeda XIII Andromeda XIV Andromeda XV Andromeda XVI Andromeda XVII Andromeda XVIII Andromeda XIX Andromeda XX Andromeda XXI Andromeda XXII Andromeda XXIII Andromeda XXIV Andromeda XXV Andromeda XXVI Andromeda XXVII Andromeda XXVIII Andromeda XXIX Triangulum subgroup* *It is uncertain whether these are companion galaxies of the Andromeda Galaxy
Catalogued stars	AE Andromedae AF Andromedae M31-RV
Other	Andromeda–Milky Way collision S Andromedae Mayall II M32p NGC 206 3XMM J004232.1 411314
Category