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The properties of starless cores in intermediate-/high-mass protoclusters

The properties of starless cores in intermediate-/high-mass protoclusters. M. Audard ISDC & Observatoire de Geneve T.L. Bourke Harvard-Smithsonian CfA , Boston G. Busquet Universitat de Barcelona P . Caselli University of Leeds

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The properties of starless cores in intermediate-/high-mass protoclusters

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  1. The properties of starless cores in intermediate-/high-mass protoclusters M. Audard ISDC & Observatoire de Geneve T.L. Bourke Harvard-SmithsonianCfA , Boston G. BusquetUniversitat de Barcelona P. Caselli UniversityofLeeds R. Cesaroni INAF-OAA, Firenze F. Gueth IRAM, Grenoble I. Jimenez-SerraHarvard-SmithsonianCfA, Boston A. Isella California InstituteofTechnology A. Palau Universitat de Barcelona A. Sanchez-MongeUniversitat de Barcelona J. TanUniversityof Florida L. Testi ESO Q. ZhangHarvard-SmithsonianCfA , Boston Francesco Fontani European Southern Observatory (ESO) Institut de RadioAstronomieMillimetrique (IRAM)

  2. Starlesscores: initialconditionsof SF! whatweknow and whatwedon’tknow • Isolated, low-mass SFRs: • basic physics: T ~ 10 K, n ~ 106 cm-3, T and n profiles • chemistry: [D/H] ~ 0.1, CO depletion • kinematics: Δv ~ thermal, infall • (e.g. Caselli et al. 2002; Crapsiet al. 2005;Kirk et al. 2007; review = Bergin & Tafalla 2007) • Clustered, low-massSFRs: • basicphysics: T ~ 13 K, n ~ 106 cm-3, T & n profiles? • chemistry: [D/H] ~ ? , CO depletion? • kinematics: Δv ~ thermal, infall? • (e.g. Andre’ et al. 2007, Friesenet al. 2009, Foster et al. 2009; Offneret al. 2008; Rathborneet al. 2008) • Clustered, high-massSFRs: • basicphysics: ~ T, ~ n • chemistry: ~ CO depletion • kinematics: ~ Δv • (e.g. Palau et al. 2007; Beutheret al. 2007; Beuther & Henning 2009; Zhanget al. 2009) 1- progenitors of massive stars 2- progenitors of low-mass stars in ‘extreme’ environments

  3. IRAS 05345+3157:an intermediate-/high-mass Protoclusterharboringpre-stellarcorecandidates d ~ 1.8 kpc starless IM protostar protostar?? Early-B (proto)star starless (Fontaniet al. 2009, A&A, 499, 233)

  4. 1. TEMPERATURE & LINEWIDTHS Method: From NH3 line ratio (Busquet et al. 2009) Protostars C1-a: Tk ~ 21 K C1-b: Tk ~ 22 K C2: Tk ~ 17 K C3: Tk ~ 17 K Starless N: Tk ~ 13 K S: Tk ~ 16 K N N S S (Fontanietal., in preparation) σth ~ 0.05 – 0.15 km s-1 Starless cores in I05345 HOTTER than isolated ones in low-mass SFRs …and they are dominated by NON-THERMAL MOTIONS

  5. 2. CHEMISTRY 1: DEUTERATION Green = N2H+ (PdBI) Grey = 3mm (PdBI) Red = N2D+ (SMA) N:N(N2D+)/N(N2H+) = 0.1 S:N(N2D+)/N(N2H+) = 0.1 Mvir = 6MsunMvir = 3Msun MX = 9Msun MX= 2Msun Fontani et al. (2008) Deuterium Fractionation SIMILAR to that measured in isolated pre-stellar cores

  6. 3. CHEMISTRY 2: N(NH3) vs N(N2H+) In low-mass SFRs, NH3/N2H+ higher in less evolved objects: CHEMICAL CLOCK (Caselli et al. 2002; Hotzel et al. 2004; Palau et al. 2007; models of Aikawa et al. 2003) N(NH3)/N(N2H+) Protostellar C1-a: 37 C1-b: 28 C2: 298 Starless N: 571 S: 416 Fontani et al. 2010, in preparation NH3/N2H+SIMILAR to what’s found in low-mass SFRs

  7. Starlesscores in IRAS 20293+3952 Palau et al. (2007) Busquet et al. (2010) • LINEWIDTH: • 0.4 – 1.3 km s-1 (starless) • TEMPERATURE: • 14 – 19 K (starless) • 24 K (protostellar) • DEUTERATION, N(NH2D)/N(NH3): • 0.1 – 0.8 (starless) !!!!!!!!! • <0.1 (protostellar) • NH3/N2H+: • ~300 (starless) • ~50 (protostellar)

  8. IRAS 20343+4129: starlesscores in between anoutflow and a cavity d ~ 1.4 kpc Image = 2.12μm (2MASS) IRS 2 Grey = NH3(1,1) (VLA) White = 1mm cont. (SMA) Starless Starless UC HII 0.05 pc Palau et al. (2007); Kumar et al. (2002); Beuther et al. (2002)

  9. IRAS 20343+4129: new CARMA observations (Fontanietal., in preparation)

  10. IRAS 20343+4129: new CARMA observations (Fontanietal., in preparation)

  11. IRAS 20343+4129: new CARMA observations (Fontanietal., in preparation)

  12. IRAS 20343+4129: new CARMA observations (Fontanietal., in preparation)

  13. NH2D condensations : summary Line widths C B D A Courtesy of A. Palau DfracΔv Mc (20K) Mc (10K) Mvirn(H2)NH3/N2H+ km/s M M M x106 cm-3 ------------------------------------------------------------------------------------------------------------ A: 0.08 1.1 23 -- 8 5.5 29 B: 0.1 1.1 9 20 6 6.6 > 70 C: 0.13 0.9 16 36 5 4.7 19 D: 0.06 0.7 <~2 <~ 6 2 4.2 -- -------------------------------------------------------------------------------------------------------------

  14. IRAS 22134+5834: an UC HII surroundedby dense gas d~ 2.6 kpc IR (2μm, UKIRT): Kumar et al. (2002) Molecular lines (CARMA): Fontani et al. in prep. UC HII 0.1 pc

  15. Starlesscores in IRAS 22134+5834: summary Line widths Temperature Courtesy of G. Busquet Deuteration (NH2D/NH3) NH3/N2H+ 0.06 in the northern core < 0.01 elsewhere ~ 100 (starless) >~ 400 (star-forming)

  16. Starlesscores in intermediate-/high-massSFRs: COMPARISON withlow-massSFRs DIFFERENCES: Kinetic temperature higher Line widths MUCH higher SIMILARITIES: Deuterium fractionation high (but not in IRAS 22134……) ?  ?: NH3/N2H+ abundance open questions: 1- can thesepropertiesbeconsidered ‘typical’ ? IMPROVE STATISTICS 2- otheraspectsofchemistry? EXPAND SPECTRAL ANALYSIS 3-internalphysical/chemicalstructure? IMPROVE RESOLUTION

  17. Thankyou!

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