OBSERVATIONS OF GALAXY IC342 IN NARROW BAND [SII] AND Hα FILTERS ANDJELIC, M. M., ARBUTINA, B., UROSEVIC, D., DOBARDZIC, A., PAVLOVIC, M. Z. 1Department of Astronomy, Faculty of Mathematics, University of Belgrade, Serbia

Emission nebula detection in optical range [SII]/Hα emission-line ratios Shock-heated SNRs > 0.4 photoionized nebulae < 0.4 (Blair & Long 2004, Matonick & Fesen 1997) Observations in red continuum, [SII] and Hα narrow band filters Data reduction Low fluxes – long exposures – tracking problems Continuum subtraction from emission-line Absolute calibration with non-standard narrow-band filters IRAF and IRIS software -ovde treba naglasiti zahtevnost posmatranja u uskim filterima -kao i to sto trazimo izvore vrlo malog sjaja, na rubu mogucnosti teleskopa

IC342 galaxy – nearby galaxy Aim – optical detection of supernova remnants and HII region candidates IC342 galaxy – nearby galaxy large spiral, almost face-on galaxy, app. diameter ~20’ near Galactic plane, b ≈ 10º heavily obscured by Galactic extinction (A ~ 1.5mag) the most distance determinations are between 2 - 4 Mpc -interesantno je da je ova galaksija vrlo slicna M81, i isto bi izgledala na nebu, samo da se ne nalazi toliko blizu Galaktickoj ravni

Previous observations 4 SNR candidates, detected in optical range (D’Odorico et al. 1980) Numerous observations in radio and X range, a few SNR candidates (Hummel & Grave 1990, Kong 2003, Mak et al. 2011) Numerous HII regions (Hodge & Kennicutt 1983) Tooth nebula – ultra-luminous X-ray source with optical, shock-heated counterpart

ROZHEN Observations 27th & 28th of November 2011 Telescope characteristics 2 m Ritchey-Chrétien-Coudé teleskope at the National Astronomical Observatory, Rozhen, Bulgaria Focal lenght 16m CCD camera: VersArray1300B, 1340x1300 px, scale 0”.257732/px Field of view 5’45”x 5’35” Observations 27th & 28th of November 2011 Exposure time 15 minutes 3 exposures through each filter Three fields of view Narrow band filters characteristics Filter name λ0 [Å] FWHM [Å] Tmax [%] Hα 6572 32 86,7 [SII] 6719 33 83,3 Red continuum 6416 26 58

-trece polje je posmatrano u non-photometric uslovima, tj bila je slaba oblacnost

Results 13 SNR candidates 11 new SNR candidates Tooth-nebula SNR2 from D’Odorico et al. (1980) Note: SNR3 from D’Odorico et al. (1980) is HII region candidate!!! 374 HII region candidates in two fields of view (5’x5’) 666 HII region candidates in entire IC 342 (20’x20’), only positions, without fluxes (Hodge & Kennicutt 1983)

Optical SNR candidates in IC 342 galaxy

FOV1 Hα image, continuum substracted

FOV2 Hα image, continuum substracted

Future prospects Completing galactic and extragalactic SNR and HII region samples ∑ – D relations for SNRs and HII regions Star formation rate … Optical observations are convenient method for this purpose (1 - 2 m telescopes are enough for observations of nearby galaxies) – Rozen, Vidojevica, Antalia

Regards from the Belgrade ISM gang!!!!!

THANK YOU FOR YOUR ATTENTION!