YSOs toward IRAS 22147+5948 in outer Galaxy

DOI

Star formation in the outer Galaxy, namely, outside of the Solar circle, has not been extensively studied in part due to the low CO brightness of the molecular clouds linked with the negative metallicity gradient. Recent infrared surveys provide an overview of dust emission in large sections of the Galaxy, but they suffer from cloud confusion and poor spatial resolution at far-infrared wavelengths. We aim to develop a methodology to identify and classify young stellar objects (YSOs) in star-forming regions in the outer Galaxy and use it to resolve a long-standing disparity in terms of the distance and evolutionary status of IRAS 22147+5948. We used a support vector machine learning algorithm to complement standard color-color and color-magnitude diagrams in our search for YSOs in the IRAS 22147+5948 region, based on publicly available data from the Spitzer Mapping of the Outer Galaxy survey. The agglomerative hierarchical clustering algorithm was used to identify clusters. Then the physical properties of individual YSOs were calculated. The distances were determined using CO 1-0 from the Five College Radio Astronomy Observatory survey. We identified 13 Class I and 13 Class II YSO candidates using the color-color diagrams, along with an additional 2 and 21 sources, respectively, using the applied machine learning techniques. The spectral energy distributions of 23 sources were modeled with a star and a passive disk, corresponding to Class II objects. The models of three sources include envelopes that are typical for Class I objects. The objects were grouped into two clusters located at a distance of ~2.2 kpc and 5 clusters at ~5.6 kpc. The spatial extent of CO, radio continuum, and dust emission confirms the origin of YSOs in two distinct star-forming regions along a similar line of sight. The outer Galaxy may serve as a unique laboratory for exploring star formation across environments, on the condition that complementary methods and ancillary data are used to properly account for cloud confusion and distance uncertainties.

Cone search capability for table J/A+A/663/A133/table3 (Physical parameters for a subset of YSO Candidates in the IRAS 22147+5948 region with at least five photometry points, including one at a wavelength longer than 12um)

Cone search capability for table J/A+A/663/A133/tablea1 (Distances to YSOs based on the CO emission and the Gaia catalog (Bailer-Jones et al., 2021AJ....161..147B, Cat. I/352))

Cone search capability for table J/A+A/663/A133/tablea2 (Physical Parameters for a Subset of YSO Candidates in the IRAS 22147+5948 region with distances from the Gaia DR3 catalog)

Cone search capability for table J/A+A/663/A133/tablec1 (Near- and mid-infrared photometry of YSO candidates in the IRAS 22147+5948 field)

Cone search capability for table J/A+A/663/A133/tablec2 (Photometry of YSO candidates in the IRAS 22147+5948 field from mid-infrared to submillimeter wavelengths)

Cone search capability for table J/A+A/663/A133/tablec3 (Multi-wavelength photometry of YSO candidates in the IRAS 22147+5948 field with unknown distances)

Cone search capability for table J/A+A/663/A133/tablec4 (YSO classification obtained in this work and in Winston et al. (2019ApJ...880....9W, Cat. J/ApJ/880/9))

Identifier
DOI http://doi.org/10.26093/cds/vizier.36630133
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/A+A/663/A133
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/663/A133
Related Identifier https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/663/A133
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/A+A/663/A133
Provenance
Creator Karska A.; Koprowski M.; Solarz A.; Szczerba R.; Sewilo M.; Siodmiak N.,Elia D.; Gawronski M.; Grzesiak K.; Yung B.H.K.; Fischer W.J.,Kristensen L.E.
Publisher CDS
Publication Year 2022
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; Interstellar medium; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy