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- ID:
- ivo://CDS.VizieR/J/A+A/465/481
- Title:
- JHKL photometry of Hen 2-147
- Short Name:
- J/A+A/465/481
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Near-Infrared JHKL photometry of the symbiotic star Hen 2-147 between 1981 and 2005, monitored from the South African Astronomical Observatory (SAAO) at Sutherland. All but one observations were made on the 0.75m telescope with the MkII Infrared Photometer; the other one (on Julian Date 2446186.4) was made with the MkIII Infrared Photometer on the 1.9m telescope. The photometry is on the SAAO system, and is good to better than +/-0.03 at JHK and better than +/-0.05 at L.
- ID:
- ivo://CDS.VizieR/J/ApJ/752/148
- Title:
- {kappa}-distributed electrons and OIII em. line
- Short Name:
- J/ApJ/752/148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The measurement of electron temperatures and metallicities in H II regions and planetary nebulae (PNe) has--for several decades--presented a problem: results obtained using different techniques disagree. What is worse, they disagree consistently. There have been numerous attempts to explain these discrepancies, but none has provided a satisfactory solution to the problem. In this paper, we explore the possibility that electrons in H II regions and PNe depart from a Maxwell-Boltzmann equilibrium energy distribution. We adopt a "{kappa}-distribution" for the electron energies. Such distributions are widely found in solar system plasmas, where they can be directly measured. This simple assumption is able to explain the temperature and metallicity discrepancies in H II regions and PNe arising from the different measurement techniques. We find that the energy distribution does not need to depart dramatically from an equilibrium distribution. From an examination of data from H II regions and PNe, it appears that {kappa}>~10 is sufficient to encompass nearly all objects. We argue that the kappa-distribution offers an important new insight into the physics of gaseous nebulae, both in the Milky Way and elsewhere, and one that promises significantly more accurate estimates of temperature and metallicity in these regions.
- ID:
- ivo://CDS.VizieR/J/MNRAS/426/975
- Title:
- Kinematics of NGC 2768 from planetary nebulae
- Short Name:
- J/MNRAS/426/975
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- There are only a few tracers available to probe the kinematics of individual early-type galaxies beyond one effective radius. Here we directly compare a sample of planetary nebulae (PNe), globular clusters (GCs) and galaxy starlight velocities out to approximately four effective radii, in the S0 galaxy NGC 2768. Using a bulge-to-disc decomposition of a K-band image we assign PNe and starlight to either the disc or the bulge. We show that the bulge PNe and bulge starlight follow the same radial density distribution as the red subpopulation of GCs, whereas the disc PNe and disc starlight are distinct components. We find good kinematic agreement between the three tracers to several effective radii (and with stellar data in the inner regions). Further support for the distinct nature of the two galaxy components comes from our kinematic analysis. After separating the tracers into bulge and disc components we find the bulge to be a slowly rotating pressure-supported system, whereas the disc reveals a rapidly rising rotation curve with a declining velocity dispersion profile. The resulting Vrot/{sigma} ratio for the disc resembles that of a spiral galaxy and hints at an origin for NGC 2768 as a transformed late-type galaxy. A two-component kinematic analysis for a sample of S0s will help to elucidate the nature of this class of galaxy.
- ID:
- ivo://CDS.VizieR/J/MNRAS/369/120
- Title:
- Kinematic survey of planetary nebulae in M31
- Short Name:
- J/MNRAS/369/120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of positions, magnitudes and velocities for 3300 emission-line objects found by the Planetary Nebula Spectrograph in a survey of the Andromeda galaxy, M31. Of these objects, 2615 are found likely to be planetary nebulae (PNe) associated with M31. The survey area covers the whole of M31's disc out to a radius of 1.5{deg}. Beyond this radius, observations have been made along the major and minor axes, and the Northern Spur and Southern Stream regions. The calibrated data have been checked for internal consistency and compared with other catalogues. With the exception of the very central, high surface brightness region of M31, this survey is complete to a magnitude limit of m5007~23.75, 3.5mag into the PN luminosity function.
- ID:
- ivo://CDS.VizieR/J/MNRAS/442/3544
- Title:
- Kinematic tracers in Umbrella galaxy (NGC4651)
- Short Name:
- J/MNRAS/442/3544
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the dynamics of faint stellar substructures around the Umbrella Galaxy, NGC 4651, which hosts a dramatic system of streams and shells formed through the tidal disruption of a nucleated dwarf elliptical galaxy. We elucidate the basic characteristics of the system (colours, luminosities, stellar masses) using multiband Subaru/Suprime-Cam images. The implied stellar mass ratio of the ongoing merger event is ~1:50. We identify candidate kinematic tracers (globular clusters, planetary nebulae, HII regions) and follow up a subset with Keck/DEIMOS (DEep Imaging Multi-object Spectrograph) spectroscopy to obtain velocities. We find that 15 of the tracers are likely associated with halo substructures, including the probable stream progenitor nucleus. These objects delineate a kinematically cold feature in position-velocity phase space. We model the stream using single test particle orbits, plus a rescaled pre-existing N-body simulation. We infer a very eccentric orbit with a period of ~0.35Gyr and turning points at ~2-4 and ~40kpc, implying a recent passage of the satellite through the disc, which may have provoked the visible disturbances in the host galaxy. This work confirms that the kinematics of low surface brightness substructures can be recovered and modelled using discrete tracers - a breakthrough that opens up a fresh avenue for unravelling the detailed physics of minor merging.
- ID:
- ivo://CDS.VizieR/J/A+A/551/A53
- Title:
- Kn 26, a new quadrupolar planetary nebula
- Short Name:
- J/A+A/551/A53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Once classified as an emission line source, the planetary nebula (PN) nature of the source Kn 26 has only recently been recognized in digital sky surveys. To investigate the spectral properties and spatio-kinematical structure of Kn 26, we have obtained high spatial-resolution optical and near-IR narrow-band images, high-dispersion long-slit echelle spectra, and intermediate-resolution spectroscopic observations. The new data reveal an hourglass morphology typical of bipolar PNe. A detailed analysis of its morphology and kinematics discloses the presence of a second pair of bipolar lobes, making Kn 26 a new member of the subclass of quadrupolar PNe. The time lapse between the ejection of the two pairs of bipolar lobes is much shorter than their dynamical ages, implying a rapid change in the preferential direction of the central engine. The chemical composition of Kn 26 is particularly unusual among PNe, with a low N/O ratio (as for type II PNe) and a high helium abundance (as for type I PNe), although not atypical among symbiotic stars. Such an anomalous chemical composition may have resulted from the curtailment of the time in the asymptotic giant branch by the evolution of the progenitor star through a common envelope phase.
- ID:
- ivo://CDS.VizieR/J/ApJ/595/247
- Title:
- Line intensities in the planetary nebula NGC 5307
- Short Name:
- J/ApJ/595/247
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Echelle spectrophotometry of the planetary nebula NGC 5307 is presented. The data consist of Very Large Telescope Ultraviolet Visual Echelle Spectrograph observations in the 3100-10360{AA} range. Electron temperatures and densities have been determined using different line intensity ratios. We determine the H, He, C, and O abundances based on recombination lines; these abundances are almost independent of the temperature structure of the nebula. We also determine the N, O, Ne, S, Cl, and Ar abundances based on collisionally excited lines; the ratios of these abundances relative to that of H depend strongly on the temperature structure of the nebula.
- ID:
- ivo://CDS.VizieR/J/A+A/549/A65
- Title:
- Line intensities of NGC 6803
- Short Name:
- J/A+A/549/A65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the high-dispersion spectra of the elliptical ring shaped planetary nebula NGC 6803, secured with the Hamilton Echelle Spectrograph attached to the 3-m Shane telescope of Lick Observatory. Numerous lines from neutral to quadruply ionized ions are presented in the wavelength region from 3650 to 9900{AA}. We also use the low dispersion UV spectral data obtained with the 60-cm interstellar ultraviolet explorer.
- ID:
- ivo://CDS.VizieR/J/A+AS/121/407
- Title:
- LMC planetary nebulae positions
- Short Name:
- J/A+AS/121/407
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present identifications and accurate positions for about 280 planetary nebulae (PNe) in the Large Magellanic Cloud (LMC). These positions are needed for follow-up ground or space observations. Entire Schmidt plates have been scanned with the MAMA micro-densitometer, and PPM stars used for the astrometric reduction. The precision achieved is always better than 0.5", and better than 0.3" for most of the objects not located close to the border of the plates. Photometry in the B band is provided with an accuracy of about 0.2magnitude, except in too crowded zones where the background cannot be determined. Cross-identifications with IRAS sources have also been tabulated and discussed.
