Serpens First Results from the JCMT Gould Belt Legacy Survey

Serpens First results from the JCMT Gould Belt legacy survey

Michiel Hogerheijde (Leiden Observatory)

John Richer (Cambridge University) James Owen (Cambridge University) & the JCMT Gould Belt team & the HARP-B Science Veriﬁcation team Aim and overview

• We’ve seen what the JCMT and Spitzer Legacy surveys promise to do in the areas of star formation

• Here I present the ﬁrst results from the JCMT Gould Belt survey, using Science Veriﬁcation observations obtained in 2007, ...

• ...explore what the JCMT and Spitzer Gould Belt surveys can tell us about star formation, ...

• ...and how millimeter interferometric observations can offer further insight The JCMT Gould Belt survey

Cepheus Scorpius Ophiuchus Serpens Lupus Auriga Pipe Nebula Taurus IC5146 Orion Perseus Corona Australis The JCMT Gould Belt survey

Cepheus Scorpius Ophiuchus Serpens Lupus Auriga Pipe Nebula Taurus IC5146 Orion Perseus Corona Australis

Davis et al. (1999) The JCMT Gould Belt survey

S68 N

Cepheus Scorpius Ophiuchus SMM1 Serpens Lupus Auriga SMM3 Pipe Nebula Taurus IC5146 Orion Perseus Corona Australis SMM4 SMM2

Davis et al. (1999) HARP-B images 12CO 3-2 toward the Serpens core

• outﬂows Overlay of HARP-B 12CO with SCUBA

• driving sources

• SMM1

• SMM4

• SMM3

• ...?? HARP-B images 13CO and C18O 3-2 HARP-B images 13CO and C18O 3-2

• C18O and SCUBA very similar • trace column density • C18O optically thin HARP-B images 13CO and C18O 3-2

• C18O and SCUBA very similar • cross-identiﬁcation with Spitzer sources (MIPS + IRAC) • trace column density • Harvey et al. (2006, 2007a,b) • C18O optically thin Dense gas in Serpens (South East)

+ + • BIMA + Kitt Peak 12m observations of HCO , HCN, and N2H 1-0 at 10’’ resolution (2600 AU)

6 -3 • Three tracers of dense gas (nH~10 cm ) show very different spatial distributions: chemistry, induced by star-formation feedback?

Hogerheijde et al. (in prep) + Quiescent gas traced by N2H ...

+ 18 • N2H , C O, and SCUBA closely aligned • with one exception Hogerheijde et al. (in prep) + Quiescent gas traced by N2H ...

+ 18 • N2H , C O, and SCUBA closely aligned • with one exception Hogerheijde et al. (in prep) ...outﬂow shocks traced by HCN

• Brightest HCN spot also most blueshifted • Embedded shock front associated with SMM1 counterjet Hogerheijde et al. (in prep) Spitzer goes south

Harvey et al. (2006, 2007a,b) Bolocam imagescolddustnewlyfound clusters

– 24 – Enoch et al.(2007)

Fig. 3.— Bolocam 1.1 mm map of Serpens with the positions of the 35 sources detected above 5σ indicated by red circles. Inset maps show the densest source regions on a magniﬁed scale, including the well know Serpens core (Cluster A), and a recently identiﬁed southern cluster (Cluster B; Harvey et al. (2006)). Despite the low rms noise level reached (9.5 mJy beam−1), few sources are seen outside the cluster regions. [WILL HAVE A BETTER LOOKING ONE] JCMT images 12CO, HCO+, and HCN in cluster B

Crapsi et al. (in preparation) Distinguishing edge-on disks from embedded YSOs

• Infrared measurements alone cannot distinguish embedded objects from stars with circumstellar disks inclined at more than 65˚ • that’s 34% of objects... • A reliable tracer of disk mass is the ratio of submillimeter ﬂuxes in single-dish 16 and interferometerCrapsi e tbeamsal.: The (>15’true n’a tuvsre <2’of ’)class I YSO 14 Crapsi et al.: The true nature of class I YSO true disks true embedded Crapsi et al. (submitted) disks

apparent embedded

embedded YSOs apparent disks

Fig. 6. Millimeter flux versus envelope mass. In panel a the envelope mass is correlated to the total flux at 1.2 mm (calculated assuming a distane of 140 pc). The envelope mass can be measured by this optically thin emission, but this can hardly be used to disentangle the edge-on disks from the low-mass envelopes, because in the transition between stage I and stage II the masses of the disk and of the envelope become comparable and so are the two emissions (as shown in the right part of the plot). In panel b, we correct for the flux coming from the inner 300 AU ( 2"" at 140 pc) (obtainable with mm-interferometry) showing a much tighter ∼ correlation. In panel c we substitute the envelope mass with the ratio between disk and total mass and show that this correlates perfectly with the ratios between mm–interferometry and single–dish. Fig. 4. Traditional class indicators versus envelope mass. If the system is seen face–on (filled circles), the Table 1. Observablesenfvoerlopthe meamss isodweelllscapptureresdebnyteα,dTbinol, aFndigth.e 3depth of ices and silicates. This is not true for edge-on systems (empty triangles), and in particular for stage II YSOs which show similar values as the stage I. To separate better the edge-on systems from the face-on one on this plots, edge-on systems are offset by increasing their envelope mass by 15%. The horizontal doitte=d lin25e s◦hows the tri a=ditio3n5al◦separationi b=etw4ee5n◦class I andi = 55◦ i = 65◦ i = 75◦ i = 85◦ 3 class II, while the vertical solid 2line evidences envelope masses of 0.1 M separating stage I and stage II M = 5 10− N(H ) in disk [cm− ] 0 0 ! 3.61e+16 5.56e+20 1.07e+22 1.76e+23 2.75e+25 disk · YSOs. 2 2 Menv = 0.010 N(H2) in envelope [cm− ] 1.78e+20 2.33e+20 2.95e+20 2.60e+20 2.69e+20 3.40e+20 5.03e+20 α -0.65 -0.67 -0.69 -0.69 -0.28 -0.11 -0.26

Tbol [K] 1121 1134 1154 1154 775 356 330 2 Menv = 0.027 N(H2) in envelope [cm− ] 4.84e+20 6.34e+20 7.78e+20 8.08e+20 7.99e+20 9.55e+20 1.44e+21 α -0.63 -0.64 -0.65 -0.65 -0.25 -0.11 -0.26

Tbol [K] 1084 1089 1103 1096 729 336 314 2 Menv = 0.074 N(H2) in envelope [cm− ] 1.31e+21 1.72e+21 2.09e+21 2.49e+21 2.22e+21 2.68e+21 4.09e+21 α -0.58 -0.56 -0.57 -0.55 -0.16 -0.083 -0.21

Tbol [K] 987 971 968 946 615 279 262 2 Menv = 0.20 N(H2) in envelope [cm− ] 3.57e+21 4.68e+21 5.66e+21 7.19e+21 6.17e+21 7.48e+21 1.15e+22 α -0.43 -0.37 -0.33 -0.27 0.082 0.090 0.012

Tbol [K] 759 701 667 621 393 172 158 2 Menv = 0.55 N(H2) in envelope [cm− ] 9.72e+21 1.27e+22 1.54e+22 1.87e+22 1.77e+22 2.09e+22 3.23e+22 α -0.035 0.15 0.27 0.40 0.65 0.66 0.68

Tbol [K] 394 317 276 240 163 79 72 2 Menv = 1.5 N(H2) in envelope [cm− ] 2.64e+22 3.46e+22 4.17e+22 5.01e+22 7.02e+22 5.81e+22 8.50e+22 α 0.88 1.3 1.5 1.7 1.9 1.9 1.9

Tbol [K] 138 105 90 79 63 48 46 2 Menv = 4.0 N(H2) in envelope [cm− ] 7.18e+22 9.40e+22 1.13e+23 1.35e+23 1.74e+23 1.74e+23 2.38e+23 α 2.3 2.6 2.7 2.8 2.8 2.8 2.7

Tbol [K] 56 47 43 40 38 36 36 Potential for ALMA follow up of the Legacy surveys

• 12CO identifies outflows, velocity structure • 13CO and C18O identify condensations • submillimeter continuum & infrared identify and characterize young stars and embedded sources • Harvey et al. identify 235 YSOs in surveyed are of Serpens so far • Class 0, I, II -- need submm–infrared colors • Potential for ALMA • velocity structure from small scales to large(r) scales • detailed observations of individual embedded objects; disks; outflows • separate edge-on disks from embedded objects • move away from ‘favorite object’ approach to population statistics ...and south...

Cepheus Scorpius Ophiuchus Serpens Lupus

Pipe Nebula Taurus IC5146 Orion Corona Australis ...and south...

Cepheus Scorpius Ophiuchus Serpens Lupus

Pipe Nebula Taurus IC5146 Orion Corona Australis ...and south...

Cepheus Scorpius Ophiuchus Serpens Lupus

Pipe Nebula Taurus IC5146 Orion Corona Australis ...and south...

...and JCMT will follow soon!

A cluster of new stars forming in Serpens NASA/JPL-Caltech/L. Allen (Harvard- Smithsonian CfA) & Gould's Belt Legacy Team