Ammonia observations of Planck cold cores

Single-pointing observations of NH_3_(1,1) and (2,2) were conducted toward 672 Planck Early Cold Cores (ECCs) using the Nanshan 26-m radio telescope. Out of these sources, a detection rate of 37 (249 cores) was achieved, with a NH_3_(1,1) hyperfine structure detected in 187 cores and NH_3_(2,2) emission lines detected in 76 of them. The detection rate of NH_3_ is positively correlated with the continuum emission fluxes at a frequency of 857GHz. Among the observed 672 cores, ~22 have associated stellar and infrared objects within the beam size (~2 arcmin). This suggests that most of the cores in our sample may be starless. The kinetic temperatures of the cores range from 8.9 to 20.7K, with an average of 12.3K, indicating a coupling between gas and dust temperatures. The ammonia column densities range from 3.610^14^ to 6.0710^15^cm^-2^, with a median value of 2.0410^15cm^-2^. The fractional abundances of ammonia range from 0.3 to 9.710^-7^, with an average of 2.7*10^-7^, which is one order of magnitude larger than that of massive star-forming (MSF) regions and infrared dark clouds (IRDCs). The correlation between thermal and nonthermal velocity dispersion of the NH_3_(1,1) inversion transition indicates the dominance of supersonic nonthermal motions in the dense gas traced by NH3, and the relationship between these two parameters in Planck cold cores is weaker, with lower values observed for both parameters relative to other samples under our examination. The cumulative distribution shapes of line widths in the Planck cold cores closely resemble those of the dense cores found in regions of Cepheus, in addition to Orion L1630 and L1641, with higher values compared to Ophiuchus.

Cone search capability for table J/A+A/684/A144/tablea1 (Basic information of the observed sources)

Identifier
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/A+A/684/A144
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/684/A144
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/684/A144
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/A+A/684/A144
Provenance
Creator Berdikhan D.; Esimbek J.; Henkel C.; Zhou J.; Tang X.; Liu T.; Wu G.; Li D.,He Y.; Komesh T.; Tursun K.; Zhou D.; Imanaly E.; Jandaolet Q.
Publisher CDS
Publication Year 2024
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Exoplanet Astronomy; Interstellar medium; Natural Sciences; Observational Astronomy; Physics