Catalog of Dense Cores in the Orion a Giant Molecular Cloud

Abstract

We present Orion A giant molecular cloud core catalogs, which are based on 1.1 mm map with an angular resolution of 36 ′′ (∼ 0.07 pc) and C 18 O (J=1-0) data with an angular resolution of 26.4 ′′ (∼ 0.05 pc). We have cataloged 619 dust cores in the 1.1 mm map using the Clumpfind method. The ranges of the radius, mass, and density of these cores are estimated to be 0.01 -0.20 pc, 0.6 -1.2 × 10 2 M ⊙ , and 0.3 × 10 4 -9.2 × 10 6 cm −3 , respectively. We have identified 235 cores from the C 18 O data. The ranges of the radius, velocity width, LTE mass, and density are 0.13 -0.34 pc, 0.31 -1.31 km s −1 , 1.0 -61.8 M ⊙ , and (0.8 -17.5) × 10 3 cm −3 , respectively. From the comparison of the spatial distributions between the dust and C 18 O cores, four types of spatial relations were revealed:(1) the peak positions of the dust and C 18 O cores agree with each other (32.4% of the C 18 O cores), (2) two or more C 18 O cores are distributed around the peak position of one dust core (10.8% of the C 18 O cores), (3) 56.8% of the C 18 O cores are not associated with any dust cores, and (4) 69.3% of the dust cores are not associated with any C 18 O cores. The data sets and analysis are public.1 The data sets and annotation files for M IRIAD and KARM A of Tables 2 and 4 are available at the NRO star-formation project web site via http://th.nao.ac.jp/MEMBER/nakamrfm/sflegacy/data.html . 2 James Clerk Maxwell Telescope 2.2. The C 18 O (J=1-0) emission line 2.2.1. Core identification in the C 18 O mapThe overall distribution of the C 18 O emission and the velocity structure are described by Shimajiri et al. (2014). To identify cores from the C 18 O (J=1-0) data, we applied the Clumpfind algorithm (Williams et al. 1994) to the C 18 O (J=1-0) cube data with an angular resolution of 26 ′′ .4 and a velocity channel width of 0.104 km s −1 . Here, note that we applied the Gaussian gridding convolution function (GCF) with 22 ′′ .5 FWHM size to the original C 18 O data, resulting in the effective angular resolution of 26 ′′ .4, and did no smoothing in

THE 1.1 mm CONTINUUM SURVEY OF THE SMALL MAGELLANIC CLOUD: PHYSICAL PROPERTIES AND EVOLUTION OF THE DUST-SELECTED CLOUDS*

“…The other smaller objects also would recover a total flux of > 60%. These results are also consistent with the previous FRUIT simulation studies by Shimajiri et al (2011Shimajiri et al ( , 2015 and Komugi et al (2011).…”

Nobeyama 45 m mapping observations toward Orion A. II. Classification of cloud structures and variation of the 13CO/C18O abundance ratio due to far-UV radiation

“…′′ 5, which corresponds to 0.04 pc at the distance of Orion A. Shimajiri et al (2015) revealed that the mean size of dense cores traced by C 18 O (J = 1-0) in Orion A is 0.09 ± 0.03 pc and this gives φ C 18 O = 0.09 2 /(0.09 2 + 0.04 2 ) = 0.84. We investigate this effect on X13 CO /X C 18 O using φ13 CO = 1.0 and φ C 18 O = 0.84 as shown in figure 11a.…”

The Scaling Relations and Star Formation Laws of Mini-Starburst Complexes

“…14 http://www.cfa.harvard.edu/rtdc/CO/ To derive the SFRs of MCCs, we use the 21 cm radio continuum data from the VLA Galactic Plane Survey (VGPS, Stil et al 2006), the Canadian Galactic Plane Survey (CGPS, Taylor et al 2003), and the Southern Galactic Plane Survey (SGPS, Haverkorn et al 2006 • clumps/GMCs: Maruta et al (2010), Onishi et al (2002), Shimajiri et al (2015), Heyer et al (2009), Roman-Duval et al (2010, Evans et al (2014).…”

“…Top-Left diagram includes only literature data, Top-Right diagram includes literature data and our MCCs from this study, Bottom-Left diagram includes literature data, our MCCs and mini-starburst MCCs from this study, and Top-Right diagram includes all data and different linear fits as discussed in Equations 10-13 in Section 6.1. We note that the dense cores samples (R < 1 pc) from Maruta et al (2010), Onishi et al (2002), and Shimajiri et al (2015) are not included in the SFR analysis due to the lack of SFR measurements.…”