Hydroxy acetone(CH3 COCH2 OH)is one of the smallest molecules that contain both hydroxyl and carbonyl group on neighboring carbon atoms.This steric configuration is characteristic of saccharides and determines their b...Hydroxy acetone(CH3 COCH2 OH)is one of the smallest molecules that contain both hydroxyl and carbonyl group on neighboring carbon atoms.This steric configuration is characteristic of saccharides and determines their biochemical activity.The attempt to search for hydroxy acetone toward the massive star formation region Sagittarius B2(N)was unsuccessful.Here we report the first detection of CH3 COCH2 OH in the solar-type protostar IRAS 16293-2422 B,using the Atacama Large Millimeter Array science verification data at Band 4.In a total of 11 unblended transitions of CH3 COCH2 OH with upper level energies ranging from 86 to 246 K are identified.From our local thermodynamic equilibrium analysis,we derived that the rotational temperature of CH3 COCH2 OH is 160±21 K and the column density is(1.2±1.0)×10^16 cm^-2,which results in a fractional abundance of 7×10^-10 with respect to molecular hydrogen.In this work,we present the identification of CH3 COCH2 OH in IRAS 16293-2422 B and propose a simple formation mechanism.The unambiguous identification of hydroxyacetone may provide the basis for future study of the origin and evolution of saccharides in the interstellar medium.展开更多
Based on observations of 12CO (J=2–1), we select targets from archived Infrared Astronomical Satellite (IRAS) data of IRAS 02459+6029 and IRAS 22528+5936 as samples of cloud-cloud collision, according to the criteria...Based on observations of 12CO (J=2–1), we select targets from archived Infrared Astronomical Satellite (IRAS) data of IRAS 02459+6029 and IRAS 22528+5936 as samples of cloud-cloud collision, according to the criteria given by Vallee. Then we use the Midcourse Space Experiment (MSX) A band (8.28 μm) images and the NRAO VLA Sky Survey (NVSS) (1.4 GHz) continuum images to investigate the association between molecular clouds traced by the CO contour maps. The distribution of dust and ionized hydrogen shows an obvious association with the CO contour maps toward IRAS 02459+6029. However, in the possible collision region of IRAS 22528+5936, NVSS continuum radiation is not detected and the MSX sources are merely associated with the central star. The velocity fields of the two regions indicate the direction of the pressure and interaction. In addition, we have identified candidates of young stellar objects (YSOs) by using data from the Two Micron All Sky Survey (2MASS) in JHK bands expressed in a color-color diagram. The distribution of YSOs shows that the possible collision region is denser than other regions. All the evidence suggests that IRAS 02459+6029 could be an example of cloud-cloud collision, and that IRAS 22528+5936 could be two separate non-colliding clouds.展开更多
International Review of Administrative Sciences(ERAS)is published in three different language editions-English,French and Chinese.IRAS first appeared in 1927.It is the oldest public administration journal specifically...International Review of Administrative Sciences(ERAS)is published in three different language editions-English,French and Chinese.IRAS first appeared in 1927.It is the oldest public administration journal specifically focused on comparative and international topics.It is the official journal of the International Institute of Administrative Sciences(HAS),the European Group of Public Administration(EGPA),the International Association of Schools and Institutes of Administration(IASIA).展开更多
基金the National Key R&D Program of China(No.2017YFA0402701)by the Joint Research Fund in Astronomy(U1631237)under a cooperative agreement between the National Natural Science Foundation of China(NSFC)+2 种基金the Chinese Academy of Sciences(CAS)by the Top Talents Program of Yunnan Province(2015HA030)the NSFC(Grant No.11973075)。
文摘Hydroxy acetone(CH3 COCH2 OH)is one of the smallest molecules that contain both hydroxyl and carbonyl group on neighboring carbon atoms.This steric configuration is characteristic of saccharides and determines their biochemical activity.The attempt to search for hydroxy acetone toward the massive star formation region Sagittarius B2(N)was unsuccessful.Here we report the first detection of CH3 COCH2 OH in the solar-type protostar IRAS 16293-2422 B,using the Atacama Large Millimeter Array science verification data at Band 4.In a total of 11 unblended transitions of CH3 COCH2 OH with upper level energies ranging from 86 to 246 K are identified.From our local thermodynamic equilibrium analysis,we derived that the rotational temperature of CH3 COCH2 OH is 160±21 K and the column density is(1.2±1.0)×10^16 cm^-2,which results in a fractional abundance of 7×10^-10 with respect to molecular hydrogen.In this work,we present the identification of CH3 COCH2 OH in IRAS 16293-2422 B and propose a simple formation mechanism.The unambiguous identification of hydroxyacetone may provide the basis for future study of the origin and evolution of saccharides in the interstellar medium.
文摘Based on observations of 12CO (J=2–1), we select targets from archived Infrared Astronomical Satellite (IRAS) data of IRAS 02459+6029 and IRAS 22528+5936 as samples of cloud-cloud collision, according to the criteria given by Vallee. Then we use the Midcourse Space Experiment (MSX) A band (8.28 μm) images and the NRAO VLA Sky Survey (NVSS) (1.4 GHz) continuum images to investigate the association between molecular clouds traced by the CO contour maps. The distribution of dust and ionized hydrogen shows an obvious association with the CO contour maps toward IRAS 02459+6029. However, in the possible collision region of IRAS 22528+5936, NVSS continuum radiation is not detected and the MSX sources are merely associated with the central star. The velocity fields of the two regions indicate the direction of the pressure and interaction. In addition, we have identified candidates of young stellar objects (YSOs) by using data from the Two Micron All Sky Survey (2MASS) in JHK bands expressed in a color-color diagram. The distribution of YSOs shows that the possible collision region is denser than other regions. All the evidence suggests that IRAS 02459+6029 could be an example of cloud-cloud collision, and that IRAS 22528+5936 could be two separate non-colliding clouds.
文摘International Review of Administrative Sciences(ERAS)is published in three different language editions-English,French and Chinese.IRAS first appeared in 1927.It is the oldest public administration journal specifically focused on comparative and international topics.It is the official journal of the International Institute of Administrative Sciences(HAS),the European Group of Public Administration(EGPA),the International Association of Schools and Institutes of Administration(IASIA).
