Dynamical and chemical properties of the "starless" core L1014

被引:41
作者
Craspi, A
DeVries, CH
Huard, TL
Lee, JE
Myers, PC
Ridge, NA
Bourke, TL
Evans, NJ
Jorgensen, JK
Kauffmann, J
Lee, CW
Shirley, YL
Young, CH
机构
[1] Harvard Univ, Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA
[2] Univ Florence, Dipartimento Astron & Sci Spazio, I-50125 Florence, Italy
[3] Univ Texas, Austin, TX 78712 USA
[4] Leiden Observ, NL-2300 RA Leiden, Netherlands
[5] Max Planck Inst Radioastron, Bonn, Germany
[6] Korea Astron & Space Sci Inst, Taejon 305348, South Korea
[7] Natl Radio Astron Observ, Socorro, NM 87801 USA
来源
ASTRONOMY & ASTROPHYSICS | 2005年 / 439卷 / 03期
关键词
ISM : clouds; ISM : evolution; ISM : individual objects : L1014; ISM : molecules; ISM : jets and outflows; stars : formation;
D O I
10.1051/0004-6361:20042411
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Spitzer Space Telescope observations of a point-like source, L1014-IRS, close to the dust peak of the low-mass dense core L1014, have raised questions about its starless nature. These show the presence of an object with colors expected for an embedded protostar with the implication that L1014-IRS would be the lowest luminosity isolated protostar known, and an ideal target with which to test star formation theories at the low mass end. In order to study its molecular content and to search for the presence of a molecular outflow, we mapped L1014 in at least one transition of (CO)-C-12, N2H+, HCO+, CS, and of their isotopologues (CO)-C-13, (CO)-O-18, (CO)-O-17, N2D+, and (HCO+)-C-13, using the Five College Radio Astronomy Observatory (FCRAO), the IRAM 30 m antenna, and the Caltech Submillimeter Observatory (CSO). The data show physical and chemical properties in L1014 typical of moderately evolved dense cores: i.e. H-2 central density of a few 10(5) molecules cm(-3), estimated mass of similar to 2 M-circle dot, CO integrated depletion factor less than 10, N(N2H+) similar or equal to 6 x 10(12) cm(-2), N(N2D+)/N(N2H+) equal to 10%, and relatively broad N2H+ and N2D+ lines (0.35 km s(-1)). Infall signatures and significant velocity shifts between optically thick and optically thin tracers are not observed in the line profiles. No classical signatures of molecular outflow are found in the (CO)-C-12 and (CO)-C-13 FCRAO observations. In particular, no high velocity wings are found, and no well-defined blue-red lobes of (CO)-C-12 emission are seen in the channel maps. Sensitive, higher resolution observations will clarify the presence of a molecular outflow on a smaller scale than that probed by our observations.
引用
收藏
页码:1023 / 1032
页数:10
相关论文
共 41 条
[1]   Dust extinction and molecular cloud structure: L977 [J].
Alves, J ;
Lada, CJ ;
Lada, EA ;
Kenyon, SJ ;
Phelps, R .
ASTROPHYSICAL JOURNAL, 1998, 506 (01) :292-305
[2]   SUBMILLIMETER CONTINUUM OBSERVATIONS OF RHO OPHIUCHI-A - THE CANDIDATE PROTOSTAR VLA-1623 AND PRESTELLAR CLUMPS [J].
ANDRE, P ;
WARDTHOMPSON, D ;
BARSONY, M .
ASTROPHYSICAL JOURNAL, 1993, 406 (01) :122-141
[3]  
Andre P, 1994, MORIOND AST, P179
[4]   Discovery of an extremely young accreting protostar in Taurus [J].
André, P ;
Motte, F ;
Bacmann, A .
ASTROPHYSICAL JOURNAL, 1999, 513 (01) :L57-L60
[5]   Bipolar molecular outflows from young stars and protostars [J].
Bachiller, R .
ANNUAL REVIEW OF ASTRONOMY AND ASTROPHYSICS, 1996, 34 :111-154
[6]  
Barnard E. E., 1927, A Photographic Atlas of Selected Regions of the Milky Way
[7]   CANDIDATE SOLAR-TYPE PROTOSTARS IN NEARBY MOLECULAR CLOUD CORES [J].
BEICHMAN, CA ;
MYERS, PC ;
EMERSON, JP ;
HARRIS, S ;
MATHIEU, R ;
BENSON, PJ ;
JENNINGS, RE .
ASTROPHYSICAL JOURNAL, 1986, 307 (01) :337-349
[8]   Disappearance of N2H+ from the gas phase in the class 0 protostar IRAM 04191 [J].
Belloche, A ;
André, P .
ASTRONOMY & ASTROPHYSICS, 2004, 419 (03) :L35-L38
[9]   SURVEY OF INTER-STELLAR H-I FROM L-ALPHA ABSORPTION-MEASUREMENTS .2. [J].
BOHLIN, RC ;
SAVAGE, BD ;
DRAKE, JF .
ASTROPHYSICAL JOURNAL, 1978, 224 (01) :132-142
[10]   SPECTRAL ENERGY OF FIRST PROTOSTELLAR CORES - DETECTING CLASS-I PROTOSTARS WITH ISO AND SIRTF [J].
BOSS, AP ;
YORKE, HW .
ASTROPHYSICAL JOURNAL, 1995, 439 (02) :L55-L58