Synchrotron superbubble in the galaxy IC10 the ionized gas structure, kinematics, and emiss

We have investigated the structure, kinematics, and emission spectrum of the ionized gas in the synchrotron superbubble in the irregular galaxy IC 10 based on observations with the 6-m Special Astrophysical Observatory telescope with the SCORPIO focal redu

AstronomyLetters,vol.34,No.4,2008,pp.217-230

TranslatedfromPismavAstronomicheskiiZhurnal,vol.34,No.4,2008,pp.243-258

March17,2008

SynchrotronSuperbubbleintheGalaxyIC10:TheIonizedGas

Structure,Kinematics,andEmissionSpectrum

T.A.Lozinskaya1,A.V.Moiseev2,N.Yu.Podorvanyuk1,andA.N.Burenkov2

arXiv:0803.2435v1 [astro-ph] 17 Mar 2008

12

SternbergAstronomicalInstitute,Universitetskiipr.13,Moscow,119992Russia

SpecialAstrophysicalObservatoryRAS,NizhniiArkhyz,Karachai-CherkessianRepublic,357147Russia

thedateofreceiptandacceptanceshouldbeinsertedlater

Abstract.Wehaveinvestigatedthestructure,kinematics,andemissionspectrumoftheionizedgasinthesynchrotronsuperbubbleintheirregulargalaxyIC10basedonobservationswiththe6-mSpecialAstrophysicalObservatorytelescopewiththeSCORPIOfocalreducerinthreemodes:directimaginginthe[SII]λ(6717+6731) Alines,long-slitspectroscopy,andspectroscopywithascanningFabry–Perotinterferometer.Wehaveidenti edabright(inthe[SII]lines) lamentaryopticalshellanddetermineditsexpansionvelocity,mass,andkineticenergy.Thenatureoftheobjectisdiscussed.

Keywords.interstellarmedium,supernovaremnants,kinematicsanddynamicsofgalaxies,thegalaxyIC10.

1.Introduction

ThedwarfirregulargalaxyIC10iswidelyusedtoinves-tigatethestructure,kinematics,andemissionspectrumoftheinterstellarmediuminstarburstregions.Multipleionizedandneutralshellsandsupershells,arcandringstructureswithsizesfrom50to800–1000pc,andadif-fuseionizedgascomponentareobservedinthisgalaxy(Zucker2000;WilcotsandMiller1998;GildePazetal.2003;Leroyetal.2006;Chyzyetal.2003;andreferencestherein).Itsstellarpopulationsuggestsarecentstarburst(t=4–10Myr)andanolderstarburst(t>350Myr)(Hunter2001;Zucker2002;Masseyetal.2007).

TwofeaturesdistinguishIC10amongotherdwarfstarburstgalaxiesandmakeitsstudiesparticularlyin-teresting:

(1)TheanomalouslyhighnumberofWolf–Rayet(WR)stars,whichisafactorof20greaterthanthatintheLargeMagellanicCloud.ThespacedensityofWRstarsreaches11persquarekiloparsec(Masseyetal.1992;Richeretal.2001;MasseyandHolmes2002;Crowtheretal.2003;Masseyetal.2007;Vaccaetal.2007;andref-erencestherein).ThisisthehighestdensityofWRstarsamongthedwarfgalaxiescomparabletothatinmassivespiralgalaxies.Foranormalinitialmassfunction,suchahighdensityofWRstarsisindicativeofanalmost“si-multaneous”currentstarbursta ectingthebulkofthegalaxy.

第1页下一页