- ID:
- ivo://CDS.VizieR/J/A+A/600/A4
- Title:
- M 2-9 ^12^CO and ^13^CO channel maps
- Short Name:
- J/A+A/600/A4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- M 2-9 is a young planetary nebula (PN) that shows the characteristics of its last ejections in unprecedented detail. These last ejections are thought to trigger the post-asymptotic giant branch evolution. To assemble an overall picture of how M 2-9 was shaped, we analyzed the characteristics of the different molecular gas components and their relation with the warmer parts of the nebula that are visible in the optical domain. ^12^CO and ^13^CO J=3-2 line emission maps were obtained with the Atacama Large Millimeter/submillimeter Array with high angular-resolution and sensitivity.
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Search Results
132. M31 CO(2-1) spectra
- ID:
- ivo://CDS.VizieR/J/A+A/549/A27
- Title:
- M31 CO(2-1) spectra
- Short Name:
- J/A+A/549/A27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With IRAM-30m/HERA, we have detected CO(2-1) gas complexes within 30arcsec (100pc) from the center of M31 that amount to a minimum total mass of 4.2x10^4^M_{sun}_ (one third of the positions are detected). Averaging the whole HERA field, we show that there is no additional undetected diffuse component. Moreover, the gas detection is associated with gas lying on the far side of the M31 center as no extinction is observed in the optical, but some emission is present on infrared Spitzer maps. The kinematics is complex. (1) The velocity pattern is mainly redshifted: the dynamical center of the gas differs from the black hole position and the maximum of optical emission, and only the redshifted side is seen in our data. (2) Several velocity components are detected in some lines of sight. Our interpretation is supported by the reanalysis of the effect of dust on a complete planetary nebula sample. Two dust components are detected with respective position angles of 37deg and -66deg. This is compatible with a scenario where the superposition of the (PA=37deg) disk is dominated by the 10kpc ring and the inner 0.7kpc ring detected in infrared data, whose position angle (-66deg) we measured for the first time. The large-scale disk, which dominates the HI data, is steeply inclined (i=77deg), warped and superposed on the line of sight on the less inclined inner ring. The detected CO emission might come from both components.
- ID:
- ivo://CDS.VizieR/J/ApJ/758/133
- Title:
- Metallicity profile of M31 HII regions and PNe
- Short Name:
- J/ApJ/758/133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The oxygen abundance gradients among nebular emission line regions in spiral galaxies have been used as important constraints for models of chemical evolution. We present the largest-ever full-wavelength optical spectroscopic sample of emission line nebulae in a spiral galaxy (M31). We have collected spectra of 253 HII regions and 407 planetary nebulae (PNe) with the Hectospec multi-fiber spectrograph of the MMT. We measure the line-of-sight extinction for 199 HII regions and 333 PNe; we derive oxygen abundance directly, based on the electron temperature, for 51 PNe; and we use strong-line methods to estimate oxygen abundance for 192 HII regions and nitrogen abundance for 52 HII regions. The relatively shallow oxygen abundance gradient of the more extended HII regions in our sample is generally in agreement with the result of Zaritsky et al. (1994ApJ...420...87Z), based on only 19 M31 HII regions, but varies with the strong-line diagnostic employed. Our large sample size demonstrates that there is significant intrinsic scatter around this abundance gradient, as much as ~3 times the systematic uncertainty in the strong-line diagnostics. The intrinsic scatter is similar in the nitrogen abundances, although the gradient is significantly steeper. On small scales (deprojected distance <0.5kpc), HII regions exhibit local variations in oxygen abundance that are larger than 0.3dex in 33% of neighboring pairs. We do not identify a significant oxygen abundance gradient among PNe, but we do find a significant gradient in the [NII] ratio that varies systematically with surface brightness. Our results underscore the complex and inhomogeneous nature of the interstellar medium of M31, and our data set illustrates systematic effects relevant to future studies of the metallicity gradients in nearby spiral galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/582/170
- Title:
- M51 Planetary Nebula Candidates
- Short Name:
- J/ApJ/582/170
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of a radial velocity survey of planetary nebulae (PNe) located in the tidal features of the well-known interacting system NGC 5194/95 (M51). We find clear kinematic evidence that M51's northwestern tidal debris consists of two discrete structures that overlap in projection - NGC 5195's own tidal tail and diffuse material stripped from NGC 5194. We compare these kinematic data to a new numerical simulation of the M51 system and show that the data are consistent with the classic "single-passage" model for the encounter, with a parabolic satellite trajectory and a 2:1 mass ratio. We also comment on the spectra of two unusual objects: a high-velocity PN that may be associated with NGC 5194's halo and a possible interloping high-redshift galaxy.
- ID:
- ivo://CDS.VizieR/J/ApJS/38/351
- Title:
- M31 planetary nebulae
- Short Name:
- J/ApJS/38/351
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Finding charts and equatorial coordinates are presented for 311 planetary nebulae and for nearby reference stars in the Andromeda galaxy (M31). The standard deviation of the coordinates relative to the AGK3 is smaller than 1.0". The standard deviation of the coordinates relative to the reference stars is smaller than 0.5".
- ID:
- ivo://CDS.VizieR/J/ApJ/458/455
- Title:
- M 104 planetary nebulae
- Short Name:
- J/ApJ/458/455
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used the CTIO 4m telescope to make a complete and kinematically unbiased survey of M104 (NGC 4594; the Sombrero galaxy) for planetary nebulae (i.e., stars) out to 16 kpc. We present the positions and monochromatic [O III] lambda 5007 magnitudes of 294 planetaries, and use the observed planetary nebula luminosity function (PNLF) to measure a distance of 8.9+/-0.6Mpc to the galaxy. The luminosity-specific PN number lambda 2.5 in the halo of M104 is approximately 21.7x10^-9^L_{sun}_, which for its color (B-V)=0.95, is comparable to the values in other galaxies. We use the PNLF distance to M104 to compare its luminosity to the luminosities of the brightest galaxies in the Virgo Cluster, finding that if M104 were in the Virgo Cluster, it would be the third brightest galaxy. We combined the PNLF distance and the observed velocity corrected for Virgo infall to calculate a Hubble constant H_0_=91+/-8km/s/Mpc. We also used the PNLF distances to the NGC 1023 group, the Leo group, the Virgo Cluster, and the Fornax Cluster to derive Hubble constants corrected for Virgo infall. The values of H_0_ for M104, the NGC 1023 group, the Virgo Cluster, and the Fornax Cluster are in excellent agreement, suggesting that the PNLF distances and Schechter's linear infall model provide a self-consistent representation of the Hubble expansion and Virgo infall within most regions of the local supercluster. The unweighted mean of the four values is H_0_=84+/-4. The value of H_0_ derived for the Leo group differs by four standard deviations from the mean of the other four measurements. We conclude that there may be large peculiar motions in the spatially extended Leo spur.
- ID:
- ivo://CDS.VizieR/J/ApJ/492/62
- Title:
- M87 planetary nebulae
- Short Name:
- J/ApJ/492/62
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a wide-field [O III] {lambda}5007 survey for planetary nebulae (PN) in M87 and its surrounding halo. In all, we identify 338 PN candidates in a 16'x16' field around the galaxy; 187 of these objects are in a statistical sample that extends to m5007=27.15.
- ID:
- ivo://CDS.VizieR/J/MNRAS/369/97
- Title:
- M31 planetary nebulae velocities
- Short Name:
- J/MNRAS/369/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present radial velocities for a sample of 721 planetary nebulae in the disc and bulge of M31, measured using the WYFFOS fibre spectrograph on the William Herschel Telescope. Velocities are determined using the [OIII] {lambda}5007 emission line. Rotation and velocity dispersion are measured to a radius of 50arcmin (11.5kpc), the first stellar rotation curve and velocity dispersion profile for M31 to such a radius. Our kinematics are consistent with rotational support at radii well beyond the bulge effective radius of 1.4kpc, although our data beyond a radius of 5kpc are limited. We present tentative evidence for kinematic substructure in the bulge of M31 to be studied fully in a later work. This paper is part of an ongoing project to constrain the total mass, mass distribution and velocity anisotropy of the disc, bulge and halo of M31.
- ID:
- ivo://CDS.VizieR/J/AJ/121/362
- Title:
- Near-Infrared Spectra of IC5117
- Short Name:
- J/AJ/121/362
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Infrared spectroscopy from 0.8 to 2.5{mu}m is presented for the planetary nebula IC5117. The emission lines of IC5117 span a wide range of ionization that includes He II, [S III], [S II], [N I], and H2. The reddening measured from the hydrogen lines is E(B-V)=0.79, most of which is probably interstellar in origin. The He/H abundance ratio is 0.113+/-0.015, with approximately 10% of the helium being doubly ionized. Using our measurements of [S II] and [S III] lines and published observations of [S IV], we find a sulfur abundance, relative to hydrogen, of N(S)/N(H)=7.8 x 10^-6^, or approximately half the solar value. Fluxes and flux limits for several lines of molecular hydrogen are presented. Measurements of 1-0 transitions, together with the limits on 2-1 transitions, indicate Tvib~Trot=1900K, suggesting a purely collisional excitation mechanism. The ortho-to-para ratio is ~3, a value that is also indicative of collisional excitation. The presence of [C I] {lambda}9850 is consistent with previous studies of IC 5117 that indicated carbon is more abundant than oxygen. IC5117 follows the trend of planetary nebulae that display bipolar outflows and H2 emission to be carbon-rich. We confirm the results of Zhang & Kwok, who reported infrared continuum emission substantially in excess of that produced by the ionized gas. This emission is most likely due to hot dust (T~1300K) and accounts for roughly half of the continuum between 1.5 and 2{mu}m.
- ID:
- ivo://CDS.VizieR/J/A+AS/104/169
- Title:
- Near-IR survey of Northern PNs
- Short Name:
- J/A+AS/104/169
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
