IRAM 30 m LARGE SCALE SURVEY OF<sup>12</sup>CO(2-1) AND<sup>13</sup>CO(2-1) EMISSION IN THE ORION MOLECULAR CLOUD

Berné, O.; Marcelino, N.; Cernicharo, J.

doi:10.1088/0004-637x/795/1/13

Cited by 47 publications

(57 citation statements)

References 48 publications

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“…We mostly consider temperatures and column densities, but it also seems instructive to keep the main feedback processes in different regions in mind. While the column densities in OMC-2/3 are similar to values found in parts of OMC-1, the energy input in the former is mainly driven by outflows from low-mass protostars, while in the latter it is shared between outflows and feedback from the H II region, as discussed in Berné et al (2014) and inferred from CO and 13 CO (2−1) emission. The kinetic energy in KL was found to be dominated by feedback of massive protostars (outflows, jets, explosive motion).…”

Section: Discussionsupporting

confidence: 73%

An imaging line survey of OMC-1 to OMC-3

Brinkmann

Wyrowski

Kauffmann

et al. 2020

A&A

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Context. Recently, sensitive wide-bandwidth receivers in the millimetre regime have enabled us to combine large spatial and spectral coverage for observations of molecular clouds. The resulting capability to map the distributions of lines from many molecules simultaneously yields unbiased coverage of the various environments within star-forming regions. Aims. Our aim is to identify the dominant molecular cooling lines and characteristic emission features in the 1.3 mm window of distinct regions in the northern part of the Orion A molecular cloud. By defining and analysing template regions, we also intend to help with the interpretation of observations from more distant sources which cannot be easily spatially resolved. Methods. We analyse an imaging line survey covering the area of OMC-1 to OMC-3 from 200.2 to 281.8 GHz obtained with the PI230 receiver at the APEX telescope. Masks are used to define regions with distinct properties (e.g. column density or temperature ranges) from which we obtain averaged spectra. Lines of 29 molecular species (55 isotopologues) are fitted for each region to obtain the respective total intensity. Results. We find that strong sources like Orion KL have a clear impact on the emission on larger scales. Although not spatially extended, their line emission contributes substantially to spectra averaged over large regions. Conversely, the emission signatures of dense, cold regions like OMC-2 and OMC-3 (e.g. enhanced N2H+ emission and low HCN/HNC ratio) seem to be difficult to pick up on larger scales, where they are eclipsed by signatures of stronger sources. In all regions, HCO+ appears to contribute between 3 and 6% to the total intensity, the most stable value for all bright species. N2H+ shows the strongest correlation with column density, but not with typical high-density tracers like HCN, HCO+, H2CO, or HNC. Common line ratios associated with UV illumination, CN/HNC and CN/HCO+, show ambiguous results on larger scales, suggesting that the identification of UV illuminated material may be more challenging. The HCN/HNC ratio may be related to temperature over varying scales.

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Section: Discussionsupporting

confidence: 73%

An imaging line survey of OMC-1 to OMC-3

Brinkmann

Wyrowski

Kauffmann

et al. 2020

A&A

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“…At large scales, the gas content of the ISF has been systematically surveyed using single-dish observations of multiple CO isotopologs (Bally et al 1987;Dutrey et al 1991;Shimajiri et al 2011;Berné et al 2014;Buckle et al 2012;Shimajiri et al 2014), dense tracers (Ikeda et al 2007;Tatematsu et al 2008;Hacar et al 2017a;Friesen et al 2017;Kauffmann et al 2017), and recombination lines (Goicoechea et al 2015). Its mass distribution has also been investigated in the continuum at both (sub-)millimeter (Chini et al 1997;Johnstone & Bally 1999;Salji et al 2015) and FIR wavelengths (Lombardi et al 2014;Stutz & Kainulainen 2015) showing a series of clumps regularly spaced at scales of ∼1 pc (Dutrey et al 1991), typically referred to as the OMC 1-4 clouds (see also Peterson & Megeath 2008).…”

Section: Introductionmentioning

confidence: 99%

An ALMA study of the Orion Integral Filament

Hacar

Tafalla

Forbrich

et al. 2018

A&A

241

336

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Aim. We have investigated the gas organization within the paradigmatic Integral Shape Filament (ISF) in Orion in order to decipher whether or not all filaments are bundles of fibers. Methods. We combined two new ALMA Cycle 3 mosaics with previous IRAM 30m observations to produce a high-dynamic range N2H+ (1-0) emission map of the ISF tracing its high-density material and velocity structure down to scales of 0.009 pc (or ~2000 AU). Results. From the analysis of the gas kinematics, we identify a total of 55 dense fibers in the central region of the ISF. Independently of their location in the cloud, these fibers are characterized by transonic internal motions, lengths of ~0.15 pc, and masses per unit length close to those expected in hydrostatic equilibrium. The ISF fibers are spatially organized forming a dense bundle with multiple hub-like associations likely shaped by the local gravitational potential. Within this complex network, the ISF fibers show a compact radial emission profile with a median FWHM of 0.035 pc systematically narrower than the previously proposed universal 0.1 pc filament width. Conclusions. Our ALMA observations reveal complex bundles of fibers in the ISF, suggesting strong similarities between the internal substructure of this massive filament and previously studied lower-mass objects. The fibers show identical dynamic properties in both low- and high-mass regions, and their widespread detection in nearby clouds suggests a preferred organizational mechanism of gas in which the physical fiber dimensions (width and length) are self-regulated depending on their intrinsic gas density. Combining these results with previous works in Musca, Taurus, and Perseus, we identify a systematic increase of the surface density of fibers as a function of the total mass per-unit-length in filamentary clouds. Based on this empirical correlation, we propose a unified star-formation scenario where the observed differences between low- and high-mass clouds, and the origin of clusters, emerge naturally from the initial concentration of fibers.

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“…A large number of molecular line observations have been performed, such as in CO (e.g., Bally et al 1987;Goldsmith et al 1997;Wilson et al 2005;Peng et al 2012;Buckle et al 2012;Shimajiri et al 2011Shimajiri et al , 2014Berné et al 2014), CS (e.g., Tatematsu et al 1993Tatematsu et al , 1998, N 2 H + (e.g., Tatematsu et al 2008;Melnick et al 2011;Hacar et al 2017), NH 3 (e.g., Batrla et al 1983;Bastien et al 1985;Murata et al 1990;Wiseman & Ho 1996Batrla & Wilson 2003;Friesen et al 2017), H 2 CO (e.g., Thaddeus et al 1971;Kutner et al 1976;Cohen & Few 1981;Batrla et al 1983;Bastien et al 1985;Mangum et al 1990van der Wiel et al 2009;Leurini et al 2010), HC 3 N (e.g., Martín-Pintado et al 1990;Rodríguez et al 1992;Bergin et al 1996), and HCN (e.g., Schilke et al 1992;Melnick et al 2011). These observations revealed the distribution of the dense gas within OMC-1 down to a ∼0.1 pc scale.…”

Section: Introductionmentioning

confidence: 99%

Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde

Tang

Henkel

Menten

et al. 2017

A&A

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We mapped the kinetic temperature structure of the Orion molecular cloud 1 (OMC-1) with para-H 2 CO (J KaKc = 3 03 -2 02 , 3 22 -2 21 , and 3 21 -2 20 ) using the APEX 12 m telescope. This is compared with the temperatures derived from the ratio of the NH 3 (2,2)/(1,1) inversion lines and the dust emission. Using the RADEX non-LTE model, we derive the gas kinetic temperature modeling the measured averaged line ratios of para-H 2 CO 3 22 -2 21 /3 03 -2 02 and 3 21 -2 20 /3 03 -2 02 . The gas kinetic temperatures derived from the para-H 2 CO line ratios are warm, ranging from 30 to >200 K with an average of 62 ± 2 K at a spatial density of 10 5 cm −3 . These temperatures are higher than those obtained from NH 3 (2,2)/(1,1) and CH 3 CCH (6-5) in the OMC-1 region. The gas kinetic temperatures derived from para-H 2 CO agree with those obtained from warm dust components measured in the mid infrared (MIR), which indicates that the para-H 2 CO (3-2) ratios trace dense and warm gas. The cold dust components measured in the far infrared (FIR) are consistent with those measured with NH 3 (2,2)/(1,1) and the CH 3 CCH (6-5) line series. With dust at MIR wavelengths and para-H 2 CO (3-2) on one side and dust at FIR wavelengths, NH 3 (2,2)/(1,1), and CH 3 CCH (6-5) on the other, dust and gas temperatures appear to be equivalent in the dense gas (n(H 2 ) 10 4 cm −3 ) of the OMC-1 region, but provide a bimodal distribution, one more directly related to star formation than the other. The non-thermal velocity dispersions of para-H 2 CO are positively correlated with the gas kinetic temperatures in regions of strong non-thermal motion (Mach number 2.5) of the OMC-1, implying that the higher temperature traced by para-H 2 CO is related to turbulence on a ∼0.06 pc scale. Combining the temperature measurements with para-H 2 CO and NH 3 (2,2)/(1,1) line ratios, we find direct evidence for the dense gas along the northern part of the OMC-1 10 km s −1 filament heated by radiation from the central Orion nebula.

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IRAM 30 m LARGE SCALE SURVEY OF¹²CO(2-1) AND¹³CO(2-1) EMISSION IN THE ORION MOLECULAR CLOUD

Cited by 47 publications

References 48 publications

An imaging line survey of OMC-1 to OMC-3

An imaging line survey of OMC-1 to OMC-3

An ALMA study of the Orion Integral Filament

Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde

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IRAM 30 m LARGE SCALE SURVEY OF12CO(2-1) AND13CO(2-1) EMISSION IN THE ORION MOLECULAR CLOUD

Cited by 47 publications

References 48 publications

An imaging line survey of OMC-1 to OMC-3

An imaging line survey of OMC-1 to OMC-3

An ALMA study of the Orion Integral Filament

Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde

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Product

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IRAM 30 m LARGE SCALE SURVEY OF¹²CO(2-1) AND¹³CO(2-1) EMISSION IN THE ORION MOLECULAR CLOUD