WISH Water in Star forming regions with Herschel, First Results

This talk was presented at Leiden Observatory Science Day

Transcript

1. WISH Water in Star-Forming Regions with Herschel Umut A. Yildiz Ewine F. van Dishoeck, Lars E. Kristensen, Ruud Visser, Michiel Hogerheijde, Christian Brinch, Tim van Kempen, Daniel Harsono, Irene San Jose Science Day, Leiden, Sep 9, 2010 Thursday, September 9, 2010
2. WISH Team E.F. van Dishoeck, Y. Aikawa, R. Bachiller, A. Baudry, M. Benedettini, A. Benz, E. Bergin, P. Bjerkeli, G. Blake, S. Bontemps, J. Braine, A. Brandeker, C. Brinch, S. Bruderer, S. Cabrit, P. Caselli, J. Cernicharo, L. Chavarria, C. Codella, F. Daniel, C. Dedes, P. Encrenaz, A.M. di Giorgio, C. Dominik, S. Doty, H. Feuchtgruber, M. Fich, W. Frieswijk, A. Fuente, T. Giannini, J.R. Goicoechea, Th. De Graauw, D. Harsono, F. Helmich, F. Herpin, G. Herczeg, M. Hogerheijde, T. Jacq, J. Jørgensen, D. Johnstone, A. Karska, M. Kaufman, E. Keto, L. Kristensen, B. Larsson, B. Lefloch, D. Lis, R. Liseau, M. Marseille, C. McCoey, G. Melnick, D. Neufeld, B. Nisini, M. Olberg, G. Olofsson, L. Pagani, O. Panić, B. Parise, J. Pearson, R. Plume, C. Risacher, D. Salter, N. Sakai, I. San Jose, J. Santiago, P. Saraceno, R. Shipman, M. Tafalla, F. van der Tak, T. van Kempen, R. Visser, S. Viti, S. Wampfler, M. Walmsley, F. Wyrowski, S. Yamamoto, U.A. Yildiz Thursday, September 9, 2010
3. WISH Team E.F. van Dishoeck, Y. Aikawa, R. Bachiller, A. Baudry, M. Benedettini, A. Benz, E. Bergin, P. Bjerkeli, G. Blake, S. Bontemps, J. Braine, A. Brandeker, C. Brinch, S. Bruderer, S. Cabrit, P. Caselli, J. Cernicharo, L. Chavarria, C. Codella, F. Daniel, C. Dedes, P. Encrenaz, A.M. di Giorgio, C. Dominik, S. Doty, H. Feuchtgruber, M. Fich, W. Frieswijk, A. Fuente, T. Giannini, J.R. Goicoechea, Th. De Graauw, D. Harsono, F. Helmich, F. Herpin, G. Herczeg, M. Hogerheijde, T. Jacq, J. Jørgensen, D. Johnstone, A. Karska, M. Kaufman, E. Keto, L. Kristensen, B. Larsson, B. Lefloch, D. Lis, R. Liseau, M. Marseille, C. McCoey, G. Melnick, D. Neufeld, B. Nisini, M. Olberg, G. Olofsson, L. Pagani, O. Panić, B. Parise, J. Pearson, R. Plume, C. Risacher, D. Salter, N. Sakai, I. San Jose, J. Santiago, P. Saraceno, R. Shipman, M. Tafalla, F. van der Tak, T. van Kempen, R. Visser, S. Viti, S. Wampfler, M. Walmsley, F. Wyrowski, S. Yamamoto, U.A. Yildiz ~80 team members in ~35 institutes in ~10 countries ~80 team members in ~35 institutes in ~10 countries Thursday, September 9, 2010
4. WISH Water in Star-forming Regions with Herschel PI: Ewine van Dishoeck http://www.strw.leidenuniv.nl/WISH/ ✦ A 425 hr HIFI GT key-program with Herschel to study the physical and chemical structure of star forming regions focussing on H2O and its related species. ✦ Both HIFI and PACS-spectroscopy are used ✦ Program covers ~80 sources ranging from pre-stellar cores, low- to high-mass protostars in different evolutionary stages as well as protoplanetary disks. Thursday, September 9, 2010
5. ✦ Protostars emit bulk of the radiation in far-IR and submm 1.1 The birth of stars !!" !"#" !"#" !"#" AU AU $ % & 10 AU 10 # # # ' $ ( c a b d yr yr yr 1 pc 10 yr Figure 1.2: A cartoon depiction of the stages of low-mass star formation. a) An inhomogenous molecular cloud with several overdense regions, so called cloud cores. b) A cloud core is triggered into gravitational collapse when it reaches its Jeans mass. Material moves radially toward the center of the core under the influence of gravity. c) Due to turbulence and shear motions of the molecular (Brinch, PhD thesis) Low-mass Star Formation Molecular Cloud Pre-stellar Core to Class 0 Class 0 to Class I Pre-stellar core Cloud Collapse Thursday, September 9, 2010
6. A. Karska et al. 2010: APEX CHAMP+ high-J CO observations of L1527 and L483 7 Fig. 4. Top panel: CO 6-5 and CO 7-6 maps of L1527. Contour levels are 6σ, 12σ, 18σ etc. (σ(CO 6−5) = 1.5 K and σ(CO 7 − 6) = 4.1 K). Central position is marked with a X. Bottom panel: Spectral maps of L1527 in CO 6-5 (right) and CO 7-6 (left) transitions. Time Mass Prestellar Class 0 Class 1 Disks Intermediate- High-mass Low- ~80 sources ~80 sources WISH Sources (L. Kristensen) Thursday, September 9, 2010
7. ✦ Natural filter of warm gas unique probe of different physical regimes ✦ Main reservoir of oxygen affects chemistry of many other species ✦ One of the main coolants in the ISM (efficient). ✦ H2O abundance shows large variations in star-formation regions: ✦ <10-8 (cold) – 3x10-4 (warm) ✦ Water associated with life on Earth pre-stellar cores - YSO’s - disks - comets - oceans Why Water? Thursday, September 9, 2010
8. PARA 5 4 3 2 1 0 0 100 200 300 400 500 Energy [K] K C quantum number HIFI PACS BOTH J KaKc 0 00 1 11 2 02 2 11 2 20 3 13 3 22 4 04 4 13 3 31 4 22 5 15 ORTHO 0 1 2 3 4 5 1 01 1 10 2 12 2 21 3 03 3 12 3 21 4 14 3 30 4 23 5 05 ✦ Many water lines are targeted with different Eup to probe different Temperatures Water Energy Levels Thursday, September 9, 2010
9. ✦ Herschel ✦ 3.5 meter submm and far-IR telescope in space ✦ Launched in May 2009 with 3 year lifetime ✦ HIFI ✦ Single-pixel heterodyne instrument ✦ Covering 480-1910 GHz (157-625 µm): ground- state H2O lines, CO, OH, SH+, CH+, H3O+, ... ✦ Ultra-high spectral resolution (dv = 0.1 km/s), line profiles are resolved => kinematic information Observations ✦ PACS ✦ 5x5 spaxels covering 47” x 47” (7000AU x 7000AU at a distance of 150 pc) ✦ From 47-220 µm: covering numerous H2O, OH, CO, O, C+, HCN, crystalline and ice features ✦ Not too bad spectral resolution (dv = 150 km/s) Thursday, September 9, 2010
10. Higher spatial resolution and sensitivity than previous instruments Space Submm Missions Thursday, September 9, 2010
11. • Testing HIFI! • Line seen in absorption! • x100 lower than predicted • Abundance range is low due to freeze-out from 2x10-10 (center) to 5x10-9 (outer edge) w.r.t. H2 • Chemical models being improved with new data from Sackler Lab. Prestellar cores - L1544 L1544 H2O 110-101 @ 557 GHz Caselli et al. 2010 (A&A HIFI) Thursday, September 9, 2010
12. Class 0 - NGC1333 H2O in NGC1333 Star Formation Region Kristensen et al. 2010 (A&A HIFI) ✦ Broader lines found than expected! Thursday, September 9, 2010
13. • PACS observations of L1157 • H2O lighting up in outflow spots • Central protostar also shows water emission which was not seen by other outflow tracers of SiO and NH3. Nisini et al. 2010 (A&A Herschel) Class 0 - Outflows - L1157 Thursday, September 9, 2010
14. • Deepest integration with HIFI: DM Tau disk tint ~ 3h (on source only) rms ~ 1.4 mK • Below than expectations. • Tentative detection! • More observations and exciting results are coming up!! Bergin et al.: W Fig. 2. (a)–(d) H2 O spectra obtained with HIFI. A tentative fea ture is present in panel (b) for H2 O 110 –101 detected with WB between VLSR of +0.5 and +10 km s−1. A Gaussian fit to th feature is shown by the smooth grey line. The HRS data on thi ??? Bergin et al. 2010 (A&A HIFI) Protostellar disks - DM Tau Thursday, September 9, 2010
15. Long term plans: • Compare sources at different evolutionary stages • Trends with time, luminosity, envelope mass, temperature, ...??? Evolution Evolution - Time Pre-stellar Core Disk Class 0 Class 1 Thursday, September 9, 2010
16. Comparison in Mass Chavarria et al. Johnstone et al. Kristensen et al. 2010 (A&A HIFI) High Mass 105 Lo Intermediate Mass 430 Lo Low-Mass 10 Lo Thursday, September 9, 2010
17. Conclusions ✦ Great, high quality data ✦ H2O data reveal many surprises: ✦ Lines are broader than expected (shocks) and multiple components can be traced ✦ Lower than expected abundances in prestellar cores, inner envelopes and disks (freeze-out) ✦ Herschel provides key numbers in terms of gas- phase abundances, physical conditions, new species detections, etc. ✦ Interpretation is still on-going... Thursday, September 9, 2010
18. First Result Publications ~1/2 WISH 1008.1254, D. Johnstone et al., * HERSCHEL-HIFI spectroscopy of the intermediate mass protostar NGC7129 FIRS 2 1008.0867, U.A. Yildiz et al., * Herschel-HIFI observations of high-J CO lines in the NGC 1333 low-mass star-forming region 1007.4370, F. Wyrowski et al., * Variations in H2 O+/H2 O ratios toward massive star-forming regions 1007.4119, M.G. Marseille et al., * Water abundances in high-mass protostellar envelopes: Herschel observations with HIFI 1007.3986, L. Chavarria et al., * Water in massive star-forming regions: HIFI observations of W3 IRS5 1007.3408, S. Bruderer et al., * Herschel-HIFI detections of hydrides towards AFGL 2591 (Envelope emission versus tenuous cloud absorption) 1007.3370, A.O. Benz et al., * Hydrides in Young Stellar Objects: Radiation tracers in a protostar-disk-outflow system 1007.3031, L.E. Kristensen et al., * Water in low-mass star-forming regions with Herschel: HIFI spectroscopy of NGC1333 1007.2198, S. F. Wampfler et al., * Herschel observations of the hydroxyl radical (OH) in young stellar objects 1007.2129, E.A. Bergin et al., * Sensitive limits on the abundance of cold water vapor in the DM Tau protoplanetary disk 1007.1248, P.Caselli et al., * Water vapor toward starless cores: the Herschel view 1006.0210, M. Fich et al., * Herschel-PACS spectroscopy of the intermediate mass protostar NGC7129 FIRS 2 1005.4517, B. Nisini et al., * Water cooling of shocks in protostellar outflows: Herschel-PACS map of L1157 1005.2903, F.F.S. van der Tak et al., * Water abundance variations around high-mass protostars: Herschel-HIFI observations of the DR21 region 1005.2031, T.A. van Kempen et al., * Origin of the hot gas in low-mass protostars: Herschel-PACS spectroscopy of HH 46 Thursday, September 9, 2010