Spectroscopic Identification and Chemical Distribution of HII Regions in the Galactic Anti-center Area from LAMOST
arXiv:1810.07361 · doi:10.1088/1538-3873/aadf22
Abstract
We spectroscopically identify 101 Galactic HII regions using spectra from the Large Sky Area Multi- Object Fiber Spectroscopic Telescope (LAMOST) survey, cross-matched with an HII region catalog derived from the all-sky Wide-Field Infrared Survey Explorer(WISE) data. Among all HII regions in our sample, 47 sources are newly confirmed. Spatially, most of our identified HII regions are located in the anti-center area of the Galaxy. For each of the HII regions, we accurately extract and measure the nebular emission lines of the spectra, and estimate the oxygen abundances using the strong-line method. We focus on the abundance distribution of HII regions in the Galactic anti-center area. Accordingly, we derive the oxygen abundance gradient with a slope of -0.036 +/-0.004 dex/kpc, covering a range of RG from 8.1 to 19.3 kpc. In particular, we also fit the outer disk objects with a slope of -0.039 +/- 0.012 dex /kpc, which indicates that there is no flattening of the radial oxygen gradient in the outer Galactic disk.
arXiv commentaccepted by PASP, 13 pages, 5 figures
References in corpus (27)
- Composite Quasar Spectra From the Sloan Digital Sky Survey
- [O III]/[N II] as an Abundance Indicator at High Redshift
- Metallicity Calibrations and the Mass-Metallicity Relation for Star-Forming Galaxies
- Using Strong Lines to Estimate Abundances in Extragalactic HII Regions and Starburst Galaxies
- The Chemical Evolution of the Galaxy: the two-infall model
- The O3N2 and N2 abundance indicators revisited: improved calibrations based on CALIFA and Te-based literature data
- Spectroscopy of Outlying H II Regions in Spiral Galaxies: Abundances and Radial Gradients
- The WISE Catalog of Galactic HII Regions
- The Green Bank Telescope HII Region Discovery Survey II. The Source Catalog
- Eliminating Error in the Chemical Abundance Scale for Extragalactic HII Regions
- Biases in abundance derivations for metal-rich nebulae
- The Electron Temperature Gradient in the Galactic Disk
- Carbon and Oxygen Galactic Gradients: Observational Values from HII Region Recombination Lines
- The oxygen abundance in the inner HII regions of M101. Implications for the calibration of strong-line metallicity indicators
- LAMOST Spectroscopic Survey of the Galactic Anti-centre (LSS-GAC): target selection and the first release of value-added catalogues
- Ionized gaseous nebulae chemical abundance determination using the direct method
- Empirical strong-line oxygen abundance calibrations from galaxies with electron temperature measurements
- Finding Distant Galactic HII Regions
- The Green Bank Telescope Galactic H II Region Discovery Survey
- The radial abundance gradient of oxygen towards the Galactic anticentre
- Spectroscopy of two PN candidates in IC10
- Oxygen abundance distribution in Galactic disc
- Chemical distribution of HII regions towards the Galactic anticentre
- A Green Bank Telescope Survey of Large Galactic HII Regions
- Spectral classification and composites of galaxies in LAMOST DR4
- Spectroscopy of planetary nebulae in M33
- Diagnostic line ratios in the IC 1805 optical gas complex