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- ID:
- ivo://CDS.VizieR/J/A+A/552/A12
- Title:
- Abundances of PNe in NGC 300
- Short Name:
- J/A+A/552/A12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained deep spectroscopy of 26 planetary nebulae (PNe) and 9 compact HII regions in the nearby spiral galaxy NGC 300, and analyzed them together with the giant HII regions observed by Bresolin et al. (2009ApJ...700..309B). We have determined the physical properties of all those objects and their content in He, N, O, Ne, S and Ar in a consistent way. We find that compact HII regions have abundances similar to those of giant HII regions, while PNe have systematically larger N/O ratios and similar Ne/O and Ar/O ratios. We demonstrate that this nitrogen enhancement in PNe cannot be due to second dredge-up in the progenitor stars, since their initial masses are around 2-2.5M_{sun}_. An extra mixing process is required, perhaps be driven by rotation. Concerning the radial abundance distribution, PNe behave differently from HII regions: In the central parts, they show an average O/H smaller by 0.15dex. Their abundance dispersion at any galactocentric radius is significantly larger than for HII regions and many of them have O/H values higher than HII regions at the same galactocentric distance, suggesting that oxygen production in the PN progenitors in NGC 300 is common. PN abundance gradients in O/H, Ne/H and Ar/He are significantly shallower than those of HII regions. We argue that this indicates a steepening of the metallicity gradient in NGC 300 during the last Gr, rather than the effect of radial stellar motions.
- ID:
- ivo://CDS.VizieR/J/A+A/380/300
- Title:
- Abundances of PN towards Galactic bulge
- Short Name:
- J/A+A/380/300
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work we report spectrophotometric observations of a planetary nebula sample towards the galactic bulge. A total of 45 PNe was observed and their physical parameters (electron density and temperature) were derived. Ionic abundances were calculated using a three-level atom model and abundances were derived through ionisation correction factors. Results show low abundance objects at high galactic latitudes, indicating a possible vertical gradient inside the bulge. A few objects with low N/O ratio were found, which could have originated from old, low mass progenitors.
- ID:
- ivo://CDS.VizieR/J/ApJ/723/658
- Title:
- Abundances of the halo PN BoBn 1
- Short Name:
- J/ApJ/723/658
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have performed a comprehensive chemical abundance analysis of the extremely metal-poor ([Ar/H]<-2) halo planetary nebula (PN) BoBn 1 based on International Ultraviolet Explorer archive data, Subaru/High-Dispersion Spectrograph spectra, VLT/UVES archive data, and Spitzer/IRS spectra. We have detected over 600 lines in total and calculated ionic and elemental abundances of 13 elements using detected optical recombination lines (ORLs) and collisionally excited lines (CELs). The estimations of C, N, O, and Ne abundances from the ORLs and Kr, Xe, and Ba from the CELs are done the first for this nebula, empirically and theoretically. We have detected five fluorine and several slow neutron capture elements (the s-process). The amounts of [F/H], [Kr/H], and [Xe/H] suggest that BoBn 1 is the most F-rich among F-detected PNe and is a heavy s-process element rich PN. We have confirmed dust in the nebula that is composed of amorphous carbon and polycyclic aromatic hydrocarbons with a total mass of 5.8x10^-6^M_{sun}_. The photoionization models built with non-LTE theoretical stellar atmospheres indicate that the progenitor was a 1-1.5M_{sun}_ star that would evolve into a white dwarf with an ~0.62M_{sun}_ core mass and ~0.09M_{sun}_ ionized nebula. We have measured a heliocentric radial velocity of +191.6+/-1.3km/s and expansion velocity 2V_exp_ of 40.5+/-3.3km/s from an average over 300 lines.
- ID:
- ivo://CDS.VizieR/J/AN/323/484
- Title:
- Accurate coordinates of Planetary Nebulae
- Short Name:
- J/AN/323/484
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurate optical coordinates of 734 PNe, measured on the charts of the Digitized Palomar Sky Survey (DSS-2), are presented. As a result of the discussion about the external accuracy the constants -0.8" in RA and +0.8" in DEC should be added to the coordinates measured by us. They were used but rounded off already in CGPN(2000).
- ID:
- ivo://CDS.VizieR/J/ApJS/91/347
- Title:
- A 5-GHz VLA Survey of the Galactic Plane
- Short Name:
- J/ApJS/91/347
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used the VLA to survey the inner Galaxy (|b|<0.4{deg}, l=350-40{deg}) at 5GHz to a limiting sensitivity of between 2.5 and 10mJy. The survey has resulted in a catalog of 1272 discrete sources (including 100 sources outside the formal survey area) of which we have tentatively identified ~450 as ultracompact H II regions and ~45 as planetary nebulae. Approximately 30% of the radio sources are detected in the IRAS Point Source Catalog. The results confirm a scale height of only 30pc for ultracompact H II regions. We show that source lists generated from the IRAS Point Source Catalog alone suffer serious effects; the combination of the IRAS and radio surveys allows us to produce a much more complete census of the regions of massive star formation in our Galaxy.
- ID:
- ivo://CDS.VizieR/J/ApJ/711/619
- Title:
- {alpha}-element abundances in galactic PNe
- Short Name:
- J/ApJ/711/619
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we present emission line strengths, abundances, and element ratios (X/O for Ne, S, Cl, and Ar) for a sample of 38 Galactic disk planetary nebulae (PNe) consisting primarily of Peimbert classification Type I. Spectrophotometry for these PNe incorporates an extended optical/near-IR range of 3600-9600{AA} including the [SIII] lines at 9069{AA} and 9532{AA}, setting this relatively large sample apart from typical spectral coverage. We have utilized Emission Line Spectrum Analyzer, a five-level atom abundance routine, to determine Te, Ne, ionization correction factors, and total element abundances, thereby continuing our work toward a uniformly processed set of data. With a compilation of data from >120 Milky Way PNe, we present results from our most recent analysis of abundance patterns in Galactic disk PNe. With a wide range of metallicities, galactocentric distances, and both Type I and non-Type I objects, we have examined the alpha elements against HII regions and blue compact galaxies (H2BCGs) to discern signatures of depletion or enhancement in PNe progenitor stars, particularly the destruction or production of O and Ne.
- ID:
- ivo://CDS.VizieR/J/AJ/142/139
- Title:
- A new catalog of HII regions in M31
- Short Name:
- J/AJ/142/139
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new catalog of HII regions in M31. The full disk of the galaxy (~24kpc from the galaxy center) is covered in a 2.2deg^2^ mosaic of 10 fields observed with the Mosaic Camera on the Mayall 4m telescope as part of the Local Group Galaxies survey.
- ID:
- ivo://CDS.VizieR/J/A+A/405/627
- Title:
- Angular dimensions of 312 planetary nebulae
- Short Name:
- J/A+A/405/627
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of direct measurements done on H{alpha} (or H{alpha}+[NII]) images of 312 planetary nebulae. For each planetary nebulae deconvolved FWHM and resolution size from Gaussian fit and from second-moment method and direct measurement at 10% level are presented.
- ID:
- ivo://CDS.VizieR/J/MNRAS/506/3540
- Title:
- ASKAP-EMU ESP LMC Radio Continuum Survey
- Short Name:
- J/MNRAS/506/3540
- Date:
- 17 Jan 2022 11:54:41
- Publisher:
- CDS
- Description:
- We present an analysis of a new 120 deg^2^ radio continuum image of the Large Magellanic Cloud (LMC) at 888MHz with a bandwidth of 288MHz and beam size of 13.9"x12.1", from the Australian Square Kilometre Array Pathfinder (ASKAP) processed as part of the Evolutionary Map of the Universe (EMU) survey. The median Root Mean Squared noise is 58uJy/beam. We present a catalogue of 54612 sources, divided over a Gold list (30866 sources) complete down to 0.5mJy uniformly across the field, a Silver list (22080 sources) reaching down to <0.2mJy and a Bronze list (1666 sources) of visually inspected sources in areas of high noise and/or near bright complex emission. We discuss detections of planetary nebulae and their radio luminosity function, young stellar objects showing a correlation between radio luminosity and gas temperature, novae and X-ray binaries in the LMC, and active stars in the Galactic foreground that may become a significant population below this flux level. We present examples of diffuse emission in the LMC (HII regions, supernova remnants, bubbles) and distant galaxies showcasing spectacular interaction between jets and intracluster medium. Among 14333 infrared counterparts of the predominantly background radio source population we find that star-forming galaxies become more prominent below 3mJy compared to active galactic nuclei.We combine the new 888MHz data with archival Australia Telescope Compact Array data at 1.4GHz to determine spectral indices; the vast majority display synchrotron emission but flatter spectra occur too. We argue that the most extreme spectral index values are due to variability.
