In.XS: project for a future spaceborne hard x-ray all-sky survey

In.XS:pro jectforafuturespaceb ornehardX-rayall-skysurveyPhilipp e Martya,JuhoSchultzb, ClemensBaerc,d, AlexanderFritzc,eMartin Netopilc,Walter Nowotny,Michael CarrfCarlo FerrignogChristopheJeanh,Walter KoprolincJesp erRasmusseniLauraTanvuiaIvanValtchanovj,MarcosBavdazk, Rudolf Much, ArvindParmaraInstitut d'AstrophysiqueSpatialeUniversiteParis-Sud - B^at.121, F-91405 OrsaycedexbHelsinki ObservatoryUniversityof Helsinki, P.O.Box14, FIN-00014 TahtitorninmakicInstitut f ur AstronomieUniversitat Wien,Turkenschanzstr.17, A-1180 WiendInst.of Astronomy,Universitof Cambridge, Madingley Road, CB30HACambridge, UKeGottingen Obs.,Universitatssternwarte,Geismarlandstr.11, D-37083 GottingenfDunsinkObservatorySho ol of Cosmic Physics,Castlekno ckDublin 15, IrelandgS.R.O.N.Sorb onnelann2, NL-3584 CAUtrechthInstitutd'AstrophysiqueetdeGeophUniversitedeLiege, 5 av.Cointe,B-4000 LiegeiAstronomical ObservatoryUniversityof Cop enhagen,Juliane Maries Vej30,DK-2100 Cop enhagenjC.E.A./Serviced'AstrophysiqueOrme desMerisiers, Bat.709, F-91191 Gif/Yvette cedexkE.S.T.E.C./ AstrophysicsdivisionPO.BOX299, Keplerlaan 2, NL-2200 AG No ordwijkABSTRACTThe latest all-sky survey in hard X-rayband was p erformed by the HEAO-1 satellite (1380keV) with an angularresolution of 2448ar cmin.13A di use hard X-Ray background (HXB) was detected b etween 3 and 50keV16Themain scienti c goal of In.XS is to resolve a large fraction of this HXB into individual sources.As nodistortion byCompton up-scatteringisseeninthesp ectrumofmicrowavebackground,17hardX-raybackgroundisb elievedtobemainlyduepointsources.\Typ eI"ActiveGalacticNuclei(AGN)havsofter X-ray sp ectra than the hard X-ray background, so other sources must b e considered, like faint\Typ e I I" or\absorb ed" AGN. These could b e distinguished through hard X-ray sp ectroscopic or hardness ratio observations.HerewepresentIn.XS-amissionconceptdesignedtoconductthe rstimagingall-skyhardX-ray(280keV)survey.Theangularresolutionofnearly1ar cminandgoodsensitivityathighenergiesisprovidedbthe latest multilayer fo cussing mirrors, with semiconductor-based (GaAs) arrays of detectors.We also describ e themission op erations, and how the all-sky survey will b e complemented by follow-up p ointed observations of selected elds.The go o d angular resolution will allow correlations and identi cation with ob jects seen at other wavelengths.In addition, since a large fraction of the TypeIIAGN luminosity is emitted in the hard X-ray band, this survey willprovide a large unbiased sample of the AGN p opulation.This mayprovide constraints on AGN evolution throughthe p ossible observation of a turnover in deep eld source statistics.Keywords:Satellite, Hard X-RayBackground, AGN, GaAs, Multilayers...Further author information:(Send corresp ondence to P.M.)P.M.:E-mail:philipp e.marty@ias.u-psud.fr