The James Clerk Maxwell Telescope Spectral Legacy Survey

Stars form in the densest, coldest, most quiescent regions of molecular clouds. Molecules provide the only probes that can reveal the dynamics, physics, chemistry, and evolution of these regions, but our understanding of the molecular inventory of sources and how this is related to their physical state and evolution is rudimentary and incomplete. The Spectral Legacy Survey (SLS) is one of seven surveys recently approved by the James Clerk Maxwell Telescope (JCMT) Board of Directors. Beginning in 2007, the SLS will produce a spectral imaging survey of the content and distribution of all the molecules detected in the 345 GHz atmospheric window (between 332 and 373 GHz) toward a sample of five sources. Our intended targets are a low-mass core (NGC 1333 IRAS 4), three high-mass cores spanning a range of star-forming environments and evolutionary states (W49, AFGL 2591, and IRAS 20126), and a photodissociation region (the Orion Bar). The SLS will use the unique spectral imaging capabilities of HARP-B/ACSIS (Heterodyne Array Receiver Programme B/Auto-Correlation Spectrometer and Imaging System) to study the molecular inventory and the physical structure of these objects, which span different evolutionary stages and physical environments and to probe their evolution during the star formation process. As its name suggests, the SLS will provide a lasting data legacy from the JCMT that is intended to benefit the entire astronomical community. As such, the entire data set (including calibrated spectral data cubes, maps of molecular emission, line identifications, and calculations of the gas temperature and column density) will be publicly available.

[1]  A. Tielens,et al.  The H2CO abundance in the inner warm regions of low mass protostellar envelopes , 2003, astro-ph/0310536.

[2]  The Physical and Chemical Structure of Hot Molecular Cores , 2003, astro-ph/0311246.

[3]  Geoffrey A. Blake,et al.  The Impact of the Massive Young Star GL 2591 on Its Circumstellar Material: Temperature, Density, and Velocity Structure , 1999 .

[4]  P. Schilke,et al.  Observations of SiO towards photon dominated regions , 2001 .

[5]  L. Mundy,et al.  A molecular line study of NGC 1333/IRAS 4. , 1995, The Astrophysical journal.

[6]  S. Cazaux,et al.  Complex Molecules in the Hot Core of the Low-Mass Protostar NGC 1333 IRAS 4A , 2004, astro-ph/0407154.

[7]  T G Phillips,et al.  A Line Survey of Orion KL from 325 to 360 GHz , 1997, The Astrophysical journal. Supplement series.

[8]  Resetting chemical clocks of hot cores based on S-bearing molecules , 2004, astro-ph/0404246.

[9]  Massive star formation in the W49 giant molecular cloud: Implications for the formation of massive star clusters , 2004, astro-ph/0409410.

[10]  Physical-chemical modeling of the low-mass protostar IRAS 16293-2422 , 2004, astro-ph/0402610.

[11]  A. Tielens,et al.  HDO abundance in the envelope of the solar-type protostar IRAS 16293–2422 , 2004, astro-ph/0410619.

[12]  T. Millar,et al.  A 330-360 GHz spectral survey of G 34.3+0.15. I. Data and physical analysis , 1996 .

[13]  J. D. Murray,et al.  The Parkes Survey of 21-CENTIMETER Absorption in Discrete-Source Spectra. III. 21- Centimeter Absorption Measurements on 41 Galactic Sources North of Declination -48 degrees , 1972 .

[14]  Francis J. Lovas,et al.  NIST Recommended Rest Frequencies for Observed Interstellar Molecular Microwave Transitions -- 2002 Revision , 1986 .

[15]  N. Patel,et al.  Observations of Water Masers and Radio Continuum Emission in AFGL 2591 , 2003 .

[16]  F. D. Tak,et al.  Detection of Interstellar H[TINF]2[/TINF]D[TSUP]+[/TSUP] Emission , 1999 .

[17]  Minho Choi.  High-Resolution Observations of the Molecular Clouds in the NGC 1333 IRAS 4 Region , 2001 .

[18]  B. Krauskopf,et al.  Proc of SPIE , 2003 .

[19]  John E. Carlstrom,et al.  NGC 1333 IRAS 4: Further Multiplicity Revealed with the CSO-JCMT Interferometer , 1995 .

[20]  M. Allen,et al.  Hot and cold gas toward young stellar objects , 1990 .

[21]  Astrophysics,et al.  Infall, Outflow, Rotation, and Turbulent Motions of Dense Gas within NGC 1333 IRAS 4 , 2001, astro-ph/0108022.

[22]  Lee G. Mundy,et al.  Unveiling the Circumstellar Envelope and Disk: A Subarcsecond Survey of Circumstellar Structures , 1999, astro-ph/9908301.

[23]  P. Andre',et al.  Submillimeter Continuum Observations of rho Ophiuchi A: The Candidate Protostar VLA 1623 and Prestellar Clumps , 1993 .

[24]  G. Blake,et al.  Molecular Abundances and Low-Mass Star Formation. II. Organic and Deuterated Species toward IRAS 16293-2422 , 1995 .

[25]  E. Herbst,et al.  On the possible interconversion between pairs of deuterated isotopomers of methanol, its ion, and its protonated ion in star-forming regions , 2004 .

[26]  G. Fuller,et al.  The Direct Detection of a (Proto)Binary/Disk System in IRAS 20126+4104 , 2005, astro-ph/0508342.

[27]  S. Charnley.  Sulfuretted Molecules in Hot Cores , 1997 .

[28]  L. Mundy,et al.  A λ = 1.3 Millimeter Aperture Synthesis Molecular Line Survey of Orion Kleinmann-Low , 1996 .

[29]  J. Cernicharo,et al.  Deuterium Enhancement in Water toward Orion IRc2 Deduced from HDO Lines above 800 GHz , 2001 .

[30]  C. McKee,et al.  Massive star formation in 100,000 years from turbulent and pressurized molecular clouds , 2002, Nature.

[31]  R. Neri,et al.  A study of the Keplerian accretion disk and precessing outflow in the massive protostar IRAS 20126+4104 , 2005 .

[32]  Sulphur chemistry in the envelopes of massive young stars , 2002, astro-ph/0309138.

[33]  The Far-Infrared Spectrum of the Sagittarius B2 Region: Extended Molecular Absorption, Photodissociation, and Photoionization , 2003, astro-ph/0309353.

[34]  J. Bally,et al.  The Molecular Outflow and Possible Precessing Jet from the Massive Young Stellar Object IRAS 20126+4104 , 2000 .

[35]  Minho Choi.  Variability of the NGC 1333 IRAS 4A Outflow: Silicon Monoxide Observations , 2005 .

[36]  E. F. Dishoeck,et al.  Chemistry as a probe of the structures and evolution of massive star-forming regions , 2002, astro-ph/0205292.

[37]  E. F. Dishoeck,et al.  Chemical evolution of star-forming regions. , 1998, Annual review of astronomy and astrophysics.

[38]  F. Adams,et al.  Star Formation in Molecular Clouds: Observation and Theory , 1987 .

[39]  Sulfur Chemistry and Isotopic Ratios in the Starburst Galaxy NGC 253 , 2004, astro-ph/0410446.

[40]  C. Ceccarelli,et al.  Water in the envelopes and disks around young high-mass stars , 2005, astro-ph/0510640.

[41]  G. Fuller,et al.  Sulphur-bearing species as chemical clocks for low mass protostars? , 2003 .

[42]  G. Blake,et al.  Molecular line survey of Sagittarius B2(M) from 330 to 355 GHz and comparison with Sagittarius B2(N) , 1991 .

[43]  Geoffrey A. Blake,et al.  Molecular abundances in OMC-1 - the chemical composition of interstellar molecular clouds and the influence of massive star formation , 1987 .

[44]  Stafford Withington,et al.  HARP-B: a 350-GHz 16-element focal plane array for the James Clerk Maxwell telescope , 2003, SPIE Astronomical Telescopes + Instrumentation.

[45]  S. Mufson,et al.  The structure of W49 A as deduced from molecular and recombination line observations. [interstellar molecular cloud radio source] , 1977 .

[46]  L. Observatory,et al.  Molecular inventories and chemical evolution of low-mass protostellar envelopes , 2003, astro-ph/0312231.

[47]  A.G.A. Brown,et al.  A [ITAL]Hipparcos[/ITAL] Census of the Nearby OB Associations , 1998 .

[48]  L. Ziurys,et al.  Ion Chemistry in Photon-dominated Regions: Examining the [HCO+]/[HOC+]/[CO+] Chemical Network , 2000 .

[49]  D. Teyssier,et al.  The Hot Core around the Low-Mass Protostar IRAS 16293–2422: Scoundrels Rule! , 2003 .

[50]  European Southern Observatory,et al.  APEX 1 mm line survey of the Orion Bar , 2006, astro-ph/0605714.

[51]  F. Motte,et al.  A Molecular Line Survey of Orion KL in the 350 Micron Band , 2005 .

[52]  T. Graauw,et al.  Physical and chemical variations within the W3 star-forming region , 1995 .

[53]  T. Millar,et al.  A Three-Position Spectral Line Survey of Sagittarius B2 between 218 and 263 GHz. I. The Observational Data , 1998 .

[54]  P. Schilke,et al.  The extremely high-velocity molecular outflow in IRAS 20126+4104 , 2006 .

[55]  Widespread HCO Emission in the Nuclear Starburst of M82 , 2002, astro-ph/0207313.

[56]  G. White,et al.  A spectral survey of the Orion Nebula from 455-507 GHz , 2003 .

[57]  G. F. Mitchell,et al.  A CO J = 2 - 1 study of the outflow sources GL 490, GL 2591, M8E-IR, and W3 IRS 5 , 1992 .

[58]  J. Black,et al.  An atomic and molecular database for analysis of submillimetre line observations , 2004, astro-ph/0411110.

[59]  C. Ceccarelli,et al.  Abundant H(2)D+ in the pre-stellar core L1544 , 2003 .

[60]  W. Hoffmann,et al.  High-resolution far-infrared observations of H II regions - Sagittarius B2, W49, DR 21-W75 , 1977 .

[61]  M. Reid,et al.  Distance and Kinematics of the W49N H 2O Maser Outflow , 1992 .

[62]  D. Hollenbach,et al.  Water Absorption from Line-of-Sight Clouds toward W49A , 2004, astro-ph/0401482.

[63]  T. M. Bania,et al.  The Structure of Four Molecular Cloud Complexes in the BU-FCRAO Milky Way Galactic Ring Survey , 2001 .

[64]  D. Muders,et al.  The molecular cores in the L1287, AFGL 5142, and IRAS 20126 + 4104 regions , 1993 .