View source for Astronomy:3XMM J004232.1+411314

{{Short description|Neutron star}}
{{Starbox begin}}
{{Starbox observe
| epoch=[[Astronomy:J2000.0|J2000.0]] ([[Astronomy:International Celestial Reference System|ICRS]])
| ra={{RA|00|42|32.072}}<ref name=APJL2017/>
| dec={{DEC|+41|13|14.33}}<ref name=APJL2017/>
| constell=[[Astronomy:Andromeda (constellation)|Andromeda]]
}}
{{Starbox character
| variable= Low-mass X-ray binary<ref name=APJL2017/>
}}
{{Starbox reference
| Simbad = 3XMM+J004232.1%2B411314
}}
{{Starbox end}}

'''3XMM J004232.1+411314''' is a low-mass X-ray binary hosted in the galaxy [[Astronomy:Andromeda 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 [[Astronomy:Light curve|light curve]].<ref name=APJL2017/> The compact object in this system has been unambiguously identified as a [[Astronomy:Neutron star|neutron star]] with a spin period of 3 seconds.<ref name=APJL2018/>

==Identification of the source==
The [[Astronomy:Neil Gehrels Swift Observatory|Swift]] BAT all-sky survey detected hard X-rays (in the energy range 14-195 keV) in the direction of [[Astronomy:Andromeda Galaxy|M31]] and found that this emission was centered in a region 6 arcseconds away from the galaxy center. Using a subsequent [[Astronomy:NuSTAR|NuSTAR]] observation, it was found that a single source was responsible for this emission, and optical [[Astronomy:Hubble Space Telescope|HST]] images ruled out the presence of stars more massive than 3 solar masses in that direction.<ref name=Yukita2017/>

The same source was earlier observed in soft X-rays by [[Astronomy:XMM-Newton|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.<ref name=APJL2017/>

==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. <ref name=APJL2017/>
Like many others low-mass X-ray binaries, the luminosity of this source varies over time. Using [[Astronomy:XMM-Newton|XMM-Newton]] observations of Andromeda Galaxy, this source luminosity stays in the range 0.8–2.8{{e|38}} 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.<ref name=APJL2017/>

The compact object of this system is a [[Astronomy:Neutron star|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.<ref name=APJL2018/>

==References==
{{reflist|colwidth=30em|refs=
<ref name=APJL2017>{{citation | last1=Marelli | first1=M. | last2=Tiengo | first2=A. | last3=De Luca | first3=A. | last4=Salvetti | first4=D. | last5=Saronni | first5=L. | last6=Sidoli | first6=L. | last7=Paizis | first7=A. | last8=Salvaterra | first8=R. | last9=Belfiore | first9=A. | last10=Israel | first10=G. | last11=Haberl | first11=F. | last12=D'Agostino | first12=D. | date=2017 | title=Discovery of periodic dips in the brightest hard X-ray source of M31 with EXTraS | journal=The Astrophysical Journal Letters | volume=851 | issue=2 | pages=L27 | bibcode=2017ApJ...851L..27M | doi=10.3847/2041-8213/aa9b2e| arxiv=1711.05540 | s2cid=119266242 | doi-access=free }}</ref>

<ref name=APJL2018>{{citation | last1=Rodríguez Castillo | first1=G.A. | last2=Israel | first2=G.L. | last3=Esposito | first3=P. | last4=Papitto | first4=A. | last5=Stella | first5=L. | last6=Tiengo | first6=A. | last7=De Luca | first7=A. | last8=Marelli | first8=M. | date=2018 | title=Discovery of a 3 s Spinning Neutron Star in a 4.15 hr Orbit in the Brightest Hard X-Ray Source in M31 | journal=The Astrophysical Journal Letters | volume=861 | issue=2 | pages=L26 | bibcode=2018ApJ...861L..26R | doi=10.3847/2041-8213/aacf40| arxiv=1804.10858 | s2cid=119007575 | doi-access=free }}</ref>

<ref name=Yukita2017>{{citation | last1=Yukita | first1=M. | last2=Ptak | first2=A. | last3=Hornschemeier | first3=A.E. | last4=Wik | first4=D. | last5=Maccarone | first5=J. | last6=Pottschmidt | first6=K. | last7=De Luca | first7=A. | last8=Zezas | first8=A. | last9=Antoniou | first9=V. | last10=Ballhausen | first10=R. | last11=Lehmer | first11=B.D. | last12=Lien | first12=A. | last13=Williams | first13=B. | last14=Baganoff | first14=F. | last15=Boyd | first15=P.T. | last16=Enoto | first16=T. | last17=Kennea | first17=J. | last18=Page | first18=K.L. | last19=Choi | first19=Y. | date=2017 | title=Identification of the Hard X-ray Source Dominating the E > 25 keV Emission of the Nearby Galaxy M31 | journal=The Astrophysical Journal | volume=838 | issue=1 | pages=47 | bibcode=2017ApJ...838...47Y | doi=10.3847/1538-4357/aa62a3| hdl=1721.1/109690 | arxiv=1703.07318 | s2cid=118910239 | doi-access=free }}</ref>

}}

==External links==
* [https://www88.lamp.le.ac.uk/extras/wp2/plot/ublc_0505720201_PN_S001_25_500s.fit Example of two consecutive dips in an X-ray light curve of this source]{{Dead link|date=July 2023 |bot=InternetArchiveBot |fix-attempted=yes }} From EXTraS Archive.

{{Andromeda Galaxy}}
{{Andromeda (constellation)}}

[[Category:Andromeda (constellation)]]
[[Category:X-ray binaries]]
[[Category:Neutron stars]]
[[Category:Extragalactic stars]]
[[Category:Andromeda Galaxy]]

{{Sourceattribution|3XMM J004232.1+411314}}