New hard X-ray sources discovered in the ongoing INTEGRAL Galactic Plane survey after 14 years of observations
Roman Krivonos, Sergey Tsygankov, Ilya Mereminskiy, Alexander Lutovinov, Sergey Sazonov, Rashid Sunyaev
aa r X i v : . [ a s t r o - ph . H E ] A p r MNRAS , 1– ?? (0000) Preprint 27 August 2018 Compiled using MNRAS L A TEX style file v3.0
New hard X-ray sources discovered in the ongoingINTEGRAL Galactic Plane survey after 14 years ofobservations
Roman A. Krivonos, ⋆ Sergey S. Tsygankov, , Ilya A. Mereminskiy, Alexander A. Lutovinov, , Sergey Yu. Sazonov , and Rashid A. Sunyaev , Space Research Institute of the Russian Academy of Sciences, Profsoyuznaya Str. 84/32, 117997 Moscow, Russia Tuorla Observatory, Department of Physics and Astronomy, University of Turku, V¨ais¨al¨antie 20, FI-21500 Piikki¨o, Finland Moscow Institute of Physics and Technology, Institutsky per. 9, 141700 Dolgoprudny, Russia MPI f¨ur Astrophysik, Karl-Schwarzschild str. 1, Garching D-85741, Germany
27 August 2018
ABSTRACT
The International Gamma-Ray Astrophysics Laboratory (INTEGRAL) continues tosuccessfully work in orbit after its launch in 2002. The mission provides the deepestever survey of hard X-ray sources throughout the Galaxy at energies above 20 keV. Wereport on a catalogue of new hard X-ray source candidates based on the latest sky mapscomprising 14 years of data acquired with the IBIS telescope onboard
INTEGRAL inthe Galactic Plane ( | b | < . ◦ ). The current catalogue includes in total 72 hard X-ray sources detected at S / N > . σ and not known to previous INTEGRAL surveys.Among them, 31 objects have also been detected in the on-going all-sky survey by theBAT telescope of the
Swift observatory. For 26 sources on the list, we suggest possibleidentifications: 21 active galactic nuclei, two cataclysmic variables, two isolated pulsarsor pulsar wind nebulae, and one supernova remnant; 46 sources from the catalogueremain unclassified.
Key words:
X-rays: new sources
X-ray surveys play a key role in our understanding of en-ergetic phenomena in the Universe. Detailed investigationsof the physics and evolution of X-ray selected sources areusually based on systematic studies of their properties. Ob-servations in recent decades have revealed a variety of X-raypoint sources beyond the solar system in the Milky Way andMagellanic Clouds. Although the bright X-ray sources inthe Milky Way can be effectively studied, many of them arenot observable due to the heavy obscuration by the Galac-tic disk. Studies of nearby galaxies with modern sensitivesoft X-ray telescopes are relatively free from the obscurationproblem and can provide us uniform samples of X-ray bina-ries in different environments (see Fabbiano & White 2006;Fabbiano 2006, for a review). As a result, we may know bet-ter the properties of X-ray source populations and structureof the nearby galaxies, than of our own Milky Way.X-ray observations of our Galaxy at energies above 10keV are free from the obscuration bias. However, due to thelarge extent of the Milky Way across the sky, a systematic ⋆ E-mail: [email protected] survey of the Galactic X-ray source population and discoveryof new X-ray emitters require wide-angle instruments. Thismakes the IBIS coded-mask telescope (Ubertini et al. 2003)onboard the
INTEGRAL observatory (Winkler et al. 2003)unique and most suitable for surveying the Galaxy in thehard X-ray domain.The
INTEGRAL observatory has been successfully op-erating in orbit since its launch in October 2002. Overthe past years,
INTEGRAL acquired a huge data set,which allowed us to construct high quality X-ray catalogsin the Galactic Plane (GP), starting from our early pa-pers by Revnivtsev et al. (2004, 2006); Molkov et al. (2004),to more recent surveys (see Krivonos et al. 2012, 2015;Bird et al. 2016, and references therein). These works weresubsequently used for many relevant studies, includingsystematic discoveries of strongly absorbed high-mass X-ray binaries (HMXBs) and the study of their luminosityfunction and distribution in the Galaxy (Lutovinov et al.2005, 2013b; Bodaghee et al. 2007, 2012; Chaty et al. 2008;Coleiro et al. 2013), the statistics of low mass X-ray binaries(Revnivtsev et al. 2008b) and cataclysmic variables (CVs)(Revnivtsev et al. 2008a; Scaringi et al. 2010).In the previous paper (Krivonos et al. 2012), we pre- © Krivonos et al.
Figure 1.
Sensitivity of the Galactic plane surveys over theGalactic longitude averaged within | b | < ◦ in the 17 −
60 keV en-ergy band ( . σ , 1 mCrab = . × − erg s − cm − ). Blacksolid line corresponds to the 9-year survey Krivonos et al. (2012),magenta line shows the sensitivity curve from the current work.Upper panel: open and filled red circles show the positionsand fluxes of 26 non-identified persistent sources (Krivonos et al.2012; Lutovinov et al. 2013b). Filled circles denote objects iden-tified up to now. Long dashed line represents the flux limit usedby Lutovinov et al. (2013b) to achieve full completeness of thesurvey in the inner part of the Galaxy (there are no unidentifiedsources above the line). Bottom panel: blue open squares denote46 non-identified sources detected in the current survey. Filledsquares show 26 sources with tentatively identified nature. sented a GP survey ( | b | < . ◦ ) based on nine years of IN-TEGRAL operations. The survey catalogue lists 402 sourcesdetected in the − keV energy band and time-average skymaps at more than . σ significance, including 253 Galac-tic sources of known or tentatively identified nature, and 34unidentified sources. The upper panel of Fig. 1 illustratesthe limiting flux of the INTEGRAL ∼ to ∼ .The 9-year INTEGRAL
Galactic survey byKrivonos et al. (2012) and the all-sky survey by Bird et al.
Figure 2.
Face-on view of the Galaxy shown along with the dis-tance range at which an X-ray source of a given luminosity L HX (or more) can be detected according to the − keV sensitivityof the current 14-year INTEGRAL survey (solid lines), comparedto the 9-year GP survey (Krivonos et al. 2012; dotted lines). Red,orange and yellow contours correspond to L HX = × , and × erg s − , respectively. The background image is a sketch ofthe Galaxy adopted from Churchwell et al. (2009). (2016) were based on similar data sets, available by January2011 and by the end of 2010, respectively. Over about 6years that have passed since then, INTEGRAL accumulatedan additional ∼ Ms and ∼ Ms of exposure (dead-timecorrected) over the whole sky and in the GP ( | b | < . ◦ ),respectively. The increased sensitivity of the currentlyavailable INTEGRAL data set allows us to make a nextiteration in the process of finding previously unknown hardX-ray sources. Mereminskiy et al. (2016) recently releaseda − keV deep survey of three extragalactic fields (M81,Large Magellanic Cloud and 3C 273/Coma), based on 12years of observations (2003-2015) with the detection of 147sources at S / N > σ , including 37 sources observed in hardX-rays for the first time.In this short report we present a catalogue of newly dis-covered hard X-ray sources detected in the latest maps ofthe GP comprising 14 years of data acquired with INTE-GRAL /IBIS.
For this work, we selected all publicly available
INTEGRAL data from December 2002 to March 2017 (spacecraft revolu-tions 26-1790). Prior to actual data analysis we applied thelatest energy calibration (Caballero et al. 2013) for the regis-tered IBIS/ISGRI detector events with the
INTEGRAL
Of-fline Scientific Analysis version 10.2 provided by ISDC DataCentre for Astrophysics up to the
COR level. Then eventswere processed with a proprietary analysis package devel-
MNRAS , 1– ?? (0000) ew INTEGRAL sources in the GP after 14 years oped at IKI (details availiable in Krivonos et al. 2010a,2012; Churazov et al. 2014) to produce a − keV skyimage of every individual INTEGRAL observation with atypical exposure time of 2 ks (usually referred as
ScienceWindow , or
ScW ). The flux scale in each
ScW sky imagewas renormalized using the flux of the Crab nebula mea-sured in the nearest observation. This procedure was usedto account for the loss of sensitivity at low energies causedby ongoing detector degradation.In total, we obtained 124727
ScW images covering thewhole sky, comprising ∼ Ms of the effective (dead time-corrected) exposure. For the purposes of this work we se-lected 79234
ScW s ( ∼ Ms) within the GP ( | b | < . ◦ ).Following Krivonos et al. (2012) we constructed six over-lapping 70 ◦ × ◦ cartesian projections centered at the GP( | b | = ◦ ) and Galactic longitudes l = ◦ , ± ◦ , ± ◦ , and l = ◦ .The peak sensitivity of the survey is . × − erg s − cm − ( ∼ . mCrab in the 17-60 keV energy band)at a . σ detection level. The survey covers of the ge-ometrical area ( degrees) down to the flux limit of . × − erg s − cm − ( ∼ . mCrab) and of thetotal area down to the flux limit of . × − erg s − cm − ( ∼ . mCrab). Given the added exposure in the GP, theachieved improvement in sensitivity with respect to the 9-year survey is in the range of − . The updated sen-sitivity of the current survey over the Galactic longitude isshown in the bottom panel of Fig. 1. Note that the overallimprovement in sensitivity makes it possible to probe deeperinto the Galaxy. Fig. 2 shows a face-on schematic view of theGalaxy and the distances at which we can detect a hard X-ray source of a given luminosity L HX in the − keV band.One can see that (i) we can now detect all sources with theluminosity L HX > × erg s − at the far end of the Galaxyin the direction towards the Galactic Centre (GC), (ii) thedistance range for the luminosity L HX > × erg s − coversmost of the Galactic stellar mass, and (iii) the Galactic cen-tral bar is fully reachable at luminosities L HX > × ergs − . Following Krivonos et al. (2012), we adopted a con-servative detection threshold of ( S / N ) lim > . σ to ensurethat the final catalogue contains no more than one spuri-ous source assuming Poisson statistics. The regions aroundbright sources, such as Crab, Sco X-1, Cyg X-1, Cyg X-3,Vela X-1, GX 301-2, and GRS 1915+105 were excluded fromthe automated excess selection to prevent false detectionstriggered by high systematic noise. However, manual inspec-tion of these regions was performed to select possible sourcecandidates (properly marked as being detected in noisy en-vironment).A special care was taken for the source detection inthe region of ∼ degrees around the GC due to enchancedsystematics (see e.g. Krivonos et al. 2010a). False detec-tions were revealed by a distorted excess shape that dif-fers significantly from the instrumental point-spread func-tion, which is a symmetric two-dimensional Gaussian ( σ = Space Research Institute of the Russian Academy of Sciences,Moscow, Russia . × − erg s − cm − assuming aspectral shape ( E / ) − . photons cm − s − keV − . ′ ). One can reduce IBIS/ISGRI false detections by us-ing additional information from the BAT coded-mask tele-scope (Barthelmy et al. 2005) onboard the Swift observa-tory (Gehrels et al. 2004) working at hard X-ray energies.Since BAT has a different coded-mask design compared toIBIS, it suffers different systematics, which allows one to su-press the non-statistical uncertainties known to IBIS (theidea on which the combined
Swift - INTEGRAL survey byBottacini et al. 2012, is based). We assume that finding ahard X-ray counterpart in the ongoing
Swift /BAT surveys(Cusumano et al. 2010; Baumgartner et al. 2013) of a sus-pected IBIS/ISGRI systematic excess adds more evidencethat the excess is a real source.
Our analysis of 14-year averaged sky images of the GP( | b | < . ◦ ) led to the detection of 522 hard X-ray sources atsignificance S / N > . σ , which is ∼
30% more compared to402 sources detected in the 9-year survey (Krivonos et al.2012) with the same detection threshold. Note that 14weak sources listed in the 9-year survey with fluxes of . − . mCrab are not detected in the current study, prob-ably due to an intrinsic variability. Among 134 newly addedsources (522-402+14), we identified 62 previously known X-ray emitters, including 17 known sources that experiencedtransient events after 2010 (Table 1). A detailed analysisof the survey’s catalogue will be presented elsewhere. Forthe current report we selected those 72 (out of 134) newlydetected hard X-ray sources that have not been listed inthe INTEGRAL surveys based on the data acquired before2010 (Krivonos et al. 2007, 2010b, 2012; Bird et al. 2004,2006, 2007, 2010, 2016), i.e. those sources whose detectionis mainly determined by the ∼ INTEGRAL survey sensitivity.Table 2 lists new INTEGRAL sources detected inthe current work with significances between . σ and σ and fluxes between 0.17 and 1.7 mCrab ( . × − − . × − erg s − cm − ). We searched for source coun-terparts within a 3.6 ′ error circle (90% confidence), astypical for the INTEGRAL sources detected at S / N = − σ (Krivonos et al. 2007). As seen from Table 2,31 source candidates are also detected in the ongoing Swift /BAT all-sky hard X-ray survey (Cusumano et al.2010; Baumgartner et al. 2013). No any hard X-ray counter-part were found for 41 sources, thus they have been detectedin hard X-rays for the first time.We utilized also the SIMBAD and NED data bases toperform a preliminary identification of the detected sourcecandidates within 3.6 ′ of the INTEGRAL position. However,usually unique optical/IR counterparts and hence firm as-tronomical classification can only be obtained based on arc- IGR J17315 − − − − − − − − − − − − Table 2 is only available in the online version of the paper. http://simbad.u-strasbg.fr/simbad http://ned.ipac.caltech.edu MNRAS , 1– ?? (0000) Krivonos et al.
Table 1.
The list of known X-ray transients detected in 14-year time averaged map at S / N > . σ mainly due to outburst event(s)occured between 2010 and 2016.No. Name RA (J2000) Dec (J2000) Flux −
60 keV S / N Type a Outburst(deg) (deg) − erg s − cm − year1 GS 0834-430 128.979 -43.185 . ± . −
64 209.562 -64.733 . ± . − . ± . −
249 259.903 -25.020 . ± . − . ± . −
278 265.661 -27.748 . ± . −
28 266.138 -28.741 . ± . − . ± . − . ± . − . ± . − . ± . − . ± . − . ± . −
249 277.238 -25.041 . ± . −
194 278.937 -19.314 . ± . . ± . . ± . a General astrophysical type of the object: LMXB (HMXB) – low- (high-) mass X-ray binary; BHC – black hole candidate; XRB –X-ray binary. second positions provided by soft X-ray focusing telescopes.Therefore, we paid a special attention for finding soft X-raycounterparts in the HEASARC data base, Swift /XRT pointsource catalogue (1SXPS; Evans et al. 2014) and the thirdXMM-Newton serendipitous source catalogue (3XMM-DR5;Rosen et al. 2016). As a result, we suggest classification for26 sources from the list, with two (IGR J00555+4610 andIGR J18184 − ∼ . mCrab (except forIGR J16459 − . ± . mCrab).Twenty out of the 46 nonidentified sources are located in theGalactic bulge at | l | < ◦ . Regular observations of the GP with
INTEGRAL are con-sistently improving the sensitivity of the hard X-ray surveyand allowing us to extend our knowledge of the Galactic X-ray source population, both for weak and nearby sources(mostly CVs, see e.g. Lutovinov et al. 2010; Clavel et al.2016; Tomsick et al. 2016a), and more distant objects lo-cated at far end of the Galaxy (Lutovinov et al. 2016;Rahoui et al. 2017). The presented catalogue opens the pathto a large program of follow-up observations, dedicated bothto unveil new classes of objects and to increase the overallcompleteness of the source sample, needed for many Galacticpopulation studies. https://heasarc.gsfc.nasa.gov ACKNOWLEDGMENTS
This work is based on observations with
INTEGRAL , anESA project with instruments and the science data cen-tre funded by ESA member states (especially the PI coun-tries: Denmark, France, Germany, Italy, Switzerland, Spain),and Poland, and with the participation of Russia and theUSA. This research has made use of: data obtained from theHigh Energy Astrophysics Science Archive Research Center(HEASARC) provided by NASA’s Goddard Space FlightCenter; the SIMBAD database operated at CDS, Stras-bourg, France; the NASA/IPAC Extragalactic Database(NED) operated by the Jet Propulsion Laboratory, Califor-nia Institute of Technology, under contract with the NationalAeronautics and Space Administration; the Palermo BATCatalogue and database operated at INAF – IASF Palermo.The data were obtained from the European and Russian INTEGRAL
Science Data Centers. The authors are grate-ful to E.M. Churazov, who developed the INTEGRAL/IBISdata analysis methods and provided the software, and thankthe Max Planck Institute for Astrophysics for computationalsupport. This work was financially supported by RussianScience Foundation grant 14-22-00271.
REFERENCES
Barthelmy S. D., et al., 2005, Space Sci. Rev., 120, 143Baumgartner W. H., Tueller J., Markwardt C. B., Skinner G. K.,Barthelmy S., Mushotzky R. F., Evans P. A., Gehrels N., 2013,ApJS, 207, 19 http://isdc.unige.ch http://hea.iki.rssi.ru/rsdc MNRAS , 1– ?? (0000) ew INTEGRAL sources in the GP after 14 years Bikmaev I. F., Revnivtsev M. G., Burenin R. A., Sunyaev R. A.,2006, Astronomy Letters, 32, 588Bird A. J., et al., 2004, ApJLett, 607, L33Bird A. J., et al., 2006, ApJ, 636, 765Bird A. J., et al., 2007, ApJS, 170, 175Bird A. J., et al., 2010, ApJS, 186, 1Bird A. J., et al., 2016, ApJS, 223, 15Bodaghee A., et al., 2007, A&A, 467, 585Bodaghee A., Tomsick J. A., Rodriguez J., James J. B., 2012,ApJ, 744, 108Bottacini E., Ajello M., Greiner J., 2012, ApJS, 201, 34Burenin R. A., et al., 2016, Astronomy Letters, 42, 295Caballero I., et al., 2013, preprint, ( arXiv:1304.1349 )Chaty S., Rahoui F., Foellmi C., Tomsick J. A., Rodriguez J.,Walter R., 2008, A&A, 484, 783Churazov E., et al., 2014, Nature, 512, 406Churchwell E., et al., 2009, PASP, 121, 213Cieslinski D., Diaz M. P., Drake A. J., Cook K. H., 2004, PASP,116, 610Clavel M., et al., 2016, MNRAS, 461, 304Coleiro A., Chaty S., Zurita Heras J. A., Rahoui F., TomsickJ. A., 2013, A&A, 560, A108Cusumano G., et al., 2010, A&A, 524, A64Edelson R., Malkan M., 2012, ApJ, 751, 52Evans P. A., et al., 2014, ApJS, 210, 8Fabbiano G., 2006, ARA&A, 44, 323Fabbiano G., White N. E., 2006, Compact stellar X-ray sourcesin normal galaxies. pp 475–506Gehrels N., et al., 2004, ApJ, 611, 1005Huchra J. P., et al., 2012, ApJS, 199, 26Karasev D. I., Lutovinov A. A., Revnivtsev M. G., Krivonos R. A.,2012, Astronomy Letters, 38, 629Krimm H. A., et al., 2013, ApJS, 209, 14Krivonos R., Revnivtsev M., Lutovinov A., Sazonov S., ChurazovE., Sunyaev R., 2007, A&A, 475, 775Krivonos R., Revnivtsev M., Tsygankov S., Sazonov S., VikhlininA., Pavlinsky M., Churazov E., Sunyaev R., 2010a, A&A,519, A107Krivonos R., Tsygankov S., Revnivtsev M., Grebenev S., Chura-zov E., Sunyaev R., 2010b, A&A, 523, A61Krivonos R., Tsygankov S., Lutovinov A., Revnivtsev M., Chu-razov E., Sunyaev R., 2012, A&A, 545, A27Krivonos R., Tsygankov S., Lutovinov A., Revnivtsev M., Chu-razov E., Sunyaev R., 2015, MNRAS, 448, 3766Lutovinov A., Revnivtsev M., Gilfanov M., Shtykovskiy P.,Molkov S., Sunyaev R., 2005, A&A, 444, 821Lutovinov A. A., Burenin R. A., Revnivtsev M. G., SuleimanovV. F., Tkachenko A. Y., 2010, Astronomy Letters, 36, 904Lutovinov A. A., Mironov A. I., Burenin R. A., Revnivtsev M. G.,Tsygankov S. S., Pavlinsky M. N., Korobtsev I. V., EselevichM. V., 2013a, Astronomy Letters, 39, 513Lutovinov A. A., Revnivtsev M. G., Tsygankov S. S., KrivonosR. A., 2013b, MNRAS, 431, 327Lutovinov A. A., et al., 2015, Astronomy Letters, 41, 179Lutovinov A. A., Buckley D. A. H., Townsend L. J., TsygankovS. S., Kennea J., 2016, MNRAS, 462, 3823Masetti N., et al., 2010, A&A, 519, A96Masetti N., et al., 2013, A&A, 556, A120Massaro F., Paggi A., Errando M., D’Abrusco R., Masetti N.,Tosti G., Funk S., 2013, ApJS, 207, 16Mereminskiy I. A., Krivonos R. A., Lutovinov A. A., SazonovS. Y., Revnivtsev M. G., Sunyaev R. A., 2016, MNRAS,459, 140Molkov S. V., Cherepashchuk A. M., Lutovinov A. A.,Revnivtsev M. G., Postnov K. A., Sunyaev R. A., 2004,Astronomy Letters, 30, 534Paturel G., Petit C., Prugniel P., Theureau G., Rousseau J.,Brouty M., Dubois P., Cambr´esy L., 2003, A&A, 412, 45 Rahoui F., Tomsick J. A., Krivonos R., 2017, MNRAS, 465, 1563Revnivtsev M. G., et al., 2004, Astronomy Letters, 30, 382Revnivtsev M. G., Sazonov S. Y., Molkov S. V., Lutovinov A. A.,Churazov E. M., Sunyaev R. A., 2006, Astronomy Letters,32, 145Revnivtsev M., Sazonov S., Krivonos R., Ritter H., Sunyaev R.,2008a, A&A, 489, 1121Revnivtsev M., Lutovinov A., Churazov E., Sazonov S., GilfanovM., Grebenev S., Sunyaev R., 2008b, A&A, 491, 209Revnivtsev M. G., Kniazev A., Karasev D. I., Berdnikov L., Bar-way S., 2013, Astronomy Letters, 39, 523Reynolds M. T., et al., 2013, The Astronomer’s Telegram, 5200Rosen S. R., et al., 2016, A&A, 590, A1Scaringi S., et al., 2010, MNRAS, 401, 2207Sguera V., Bazzano A., Sidoli L., 2015, The Astronomer’s Tele-gram, 8250Skrutskie M. F., et al., 2006, AJ, 131, 1163Sugizaki M., Mitsuda K., Kaneda H., Matsuzaki K., YamauchiS., Koyama K., 2001, ApJS, 134, 77Tomsick J. A., Krivonos R., Rahoui F., Ajello M., Rodriguez J.,Barri`ere N., Bodaghee A., Chaty S., 2015, MNRAS, 449, 597Tomsick J. A., Rahoui F., Krivonos R., Clavel M., Strader J.,Chomiuk L., 2016a, MNRAS, 460, 513Tomsick J. A., Krivonos R., Wang Q., Bodaghee A., Chaty S.,Rahoui F., Rodriguez J., Fornasini F. M., 2016b, ApJ, 816, 38Ubertini P., et al., 2003, A&A, 411, L131Winkler C., et al., 2003, A&A, 411, L1Zolotukhin I. Y., Revnivtsev M. G., 2015, MNRAS, 446, 2418MNRAS , 1– ?? (0000) K r i v o n o s e t a l . Table 2.
The list of newly detected
INTEGRAL hard X-ray sources based on 14 years of observations.This catalogue is only available in the online version of the paper.
No. Name RA Dec Flux S/N Type Ref Hard X-ray/ γ Soft X-ray Optical/IR(deg) (deg) (17–60 keV) counterpart counterpart counterpart1 J00555+4610 13.876 46.173 . ± . . ± . . ± . . ± . − . ± . − −
266 J07141+0146 108.547 1.744 . ± . . ± . − − − . ± . − − − . ± . − − − − . ± . − − . ± . − . ± . (cid:8) . − . − (cid:9)
13 J08398 − . ± . − − − . ± . − − − − . ± . − . ± . − . ± . − − . ± . − − − . ± . . ± . − . ± . − . ± . − − . ± . − − − . ± . − − − . ± . − . ± . − . ± . − − −
428 J17040 − . ± . − − . ± . − − − − . ± . − . ± . − − − . ± . − − . ± . − . ± . − − . ± . − − . ± . − − . ± . − . ± . − . ± . − . ± . − . ± . − − . ± . − . ± . − . ± . M N R A S , ?? ( ) e w I N T E G R A L s o u r ce s i n t h e G P a f t e r y e a r s Table 2 – continued from previous page
No. Name RA Dec Flux S/N Type Ref. Hard X-ray/ γ Soft X-ray Optical/IR(deg) (deg) (17–60 keV) counterpart counterpart counterpart45 J18112 − . ± . − . ± . − . ± . − − . ± . − . ± . − . ± . − . ± . − . ± . − − . ± . − . ± . − − † . ± . . ± . . ± . (cid:8) . + . + (cid:9)
58 J19260+4136 291.517 41.608 . ± . . ± . . ± . . ± . . ± . † . ± . . ± . . ± . . ± . . ± . . ± . . ± . . ± . . ± . . ± . INTEGRAL (IGR) name of the source. A dagger symbol † marks that the source is located in the region of high systematic noise, and that its measured flux should be taken withthe caution. Equatorial coordinates (right ascension and declination) are in standard J2000.0 epoch. The measured 17–60 keV flux of the source × − erg cm − s − . General astrophysical type of the object: AGN – active galactic nucleus, SNR – supernova remnant; CV – cataclysmic variable; PSR – isolated pulsar or pulsar wind nebula (PWN).A question mark indicates that the specified type should be confirmed. References. – (1) Baumgartner et al. (2013); (2) Bikmaev et al. (2006); (3) Paturel et al. (2003); (4) Massaro et al. (2013); (5) Edelson & Malkan (2012); (6) Evans et al. (2014); (7)Masetti et al. (2010); (8) Cusumano et al. (2010); (9) Skrutskie et al. (2006); Huchra et al. (2012); (10) Krimm et al. (2013); (11) Cieslinski et al. (2004); (12) Reynolds et al. (2013);(13) Rosen et al. (2016); (14) Sguera et al. (2015); Sugizaki et al. (2001); M N R A S , ?? (0000