340 likes | 457 Views
H α imaging survey of galaxies within 10 Mpc. by Igor D.Karachentsev & Serafim S. Kaisin Special Astrophysical Observatory Russian Academy of Sciences. “Nearby Dwarf Galaxies” SAO RAS, September 14-18 2009. Growth of the Local Volume sample (D < 10 Mpc).
E N D
Hα imaging survey of galaxies within 10 Mpc by Igor D.Karachentsev & Serafim S. Kaisin Special Astrophysical Observatory Russian Academy of Sciences “Nearby Dwarf Galaxies” SAO RAS, September 14-18 2009
Growth of the Local Volume sample (D < 10 Mpc) Year Reference Number ------------------------------------------- 1979 Kraan-Korteweg & Tammann 179 1994 Karachentsev 215 2004 Karachentsev et al.=CNG 451 2009 current version of CNG 730 -------------------------------------------
Basic contributions to the Hα survey of the LV galaxies Authors Year Reference NLV Sample ------------------------------------------------------------------------------------------------------------------------ Kennicutt & Kent 1983 AJ, 88, 1094 25 S,Ir Kennicutt et al. 1989 ApJ, 337, 761 14S,Ir Hunter et al. 1993 AJ, 106, 1797 37 Ir Miller & Hodge 1994 ApJ, 427, 656 11 M81 group Young et al. 1996 AJ, 112, 1903 16 S van Zee 2000 AJ, 119, 2757 15 Ir isolated Bell & Kennicutt 2001 ApJ, 548, 681 24 S,Ir Gil de Paz et al. 2003 ApJS, 147, 29 10 BCD James et al. 2004 A&A, 414, 23 49 SO/a - Im Hunter & Elmegreen 2004 AJ, 128, 2170 50 Im, BCD Meurer et al. 2006 ApJS, 165, 307 10 HIPASS selected Epinat et al. 2008 MNRAS, 390, 466 27 S Kennicutt et al. 2008 ApJS, 178, 247 171 T>-1, B <15m,|b|>20° Bouchard et al. 2009 AJ, 137, 3038 18 Scu & CenA groups Karachentsev & Kaisin 2005 - 2010 207 All types ------------------------------------------------------------------------------------------------------------------------
Basic relations SFR(M/yr) = 1.27 · 109 FC (Hα) · D2—Gallagher et all. (1984), where D is distance in Mpc, FC is flux in (erg· cm-2· sec-1 ) corrected for the Galactic (Schlegel et all. 1998) and internal extinction A(Hα) = 0.538·AB Aint =[1.6+2.8(logVm -2.2)] · log(a/b), if Vm > 42.7 km/c, otherwise Aint = 0 Log(MHI/ M) = log FHI + 5.37 +2 · log DMpc PK=log([SFR]·T0/LK), F=log(MHI/[SFR]·T0) K – magnitudes from 2MASS or via: <B-K> =4.10 for T≤ 2 {E, SO, Sa) <B-K> =4.60 – 0.25 ·T for T= 3-8 <B-K> =2.35 for T=9,10 (Sm, BCD, Ir)
Stinson, Dalcanton et al. (2007, ApJ, 667, 170) simulated the collapse of isolated dIr's with effects of SN feedback. They found cyclic SF bursts on a scale of ~0.3 Gyr with a SFR- amplitude about 10 times for low mass dwarfs having Vm < 20 km/s.
The total star formation rate density in the Local universe( Z = 0, Ho = 72 km/s/Mpc, extinction corrected) ----------------------------------------------------------------------------------------- Log(SFR density) Reference Note Myr -1Mpc-3 --------------------------------------------------------------------------------------- -1.95 +/- 0.04 Gallego et al. 1995 em. line gg. -1.73 +/- 0.07 Tresse & Maddox 1998 I-band survey -1.64 +/- 0.02 Perez-Gonzalez et al. 2003 opt.-selected -1.66 +/- 0.08 Brinchmann et al. 2004 SDSS-based -1.81 +/- 0.03 Hanish et al. 2006 HI- selected -1.75 +/- 0.03 Salim et al. 2007 UV-based -1.72 +/- 0.08 James et al. 2008 Hα Local Univ. -1.77 +/- 0.08 present talk Hα Local vol. ----------------------------------------------------------------------------------------
Some cosmic (global) parameters (h = 0.72, Z = 0) --------------------------------------------------------------------------------------------------------------------- The critical density: 1.43 ·1011 M/Mpc3 K-luminosity density: 4.6 ·108 L/Mpc3 (Kochanek et al.2001) + (Bell et al. 2003) HI density: 0.55 ·108 M/Mpc3 HIPASS SFR density: 0.017 M/yr Mpc3 present talk PK -0.30 present talk F -0.63 present talk Fcorr -0.36 (+0.17dex HeI, +0.10dex HII) --------------------------------------------------------------------------------------------------------------------- Cosmic baryon budget (Fukugita, 2003) in the Omega-units: 0.25% (stars) + 0.08% (HI+HeI+H_2) + 0.20% (hot gas in clusters) + 2.2% (warm & cold gas) = 2.7% versus (4.4+-0.4)% from Big Bang Nucleosynthesis ---------------------------------------------------------------------------------------------------------------------
Concluding remarks and questions • We should aspire to image ALL the LV galaxies in Hα and in HI without any morphological selection. • Should we try to reach such deep limiting fluxes for survey: F(Hα) = 10-15 (erg/cm2 sec) or log[SFR] = -4.1 at D = 8 Mpc F(HI) = 0.1 Jy·km/sec or log MHI= 6.2 at D = 8 Mpc (competition with data on UV-fluxes from GALEX or EW from Sloan) • Does the quadrant {PK > 0, F > 0} is almost empty or it contains many hidden objects like HIJASS near IC2574, HI1225+01 in Virgo, and "Leib“ (AGC219303) near NGC3628 ? • SAO database for the Local Volume galaxies (N = 730) will be ready soon.