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- ID:
- ivo://CDS.VizieR/J/ApJ/721/369
- Title:
- PNe in the elliptical galaxy NGC 821
- Short Name:
- J/ApJ/721/369
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using a slitless spectroscopy method with the 8.2m Subaru telescope and its FOCAS Cassegrain spectrograph, we have increased the number of planetary nebula (PN) detections and PN velocity measurements in the flattened elliptical galaxy NGC 821. A comparison with the detections reported previously by the Planetary Nebulae Spectrograph group indicates that we have confirmed most of their detections. The velocities measured by the two groups, using different telescopes, spectrographs, and slitless techniques, are in good agreement. We have built a combined sample of 167 PNs and have confirmed the Keplerian decline of the line-of-sight velocity dispersion reported previously. We also confirm misaligned rotation from the combined sample. A dark matter halo may exist around this galaxy, but it is not needed to keep the PN velocities below the local escape velocity as calculated from the visible mass. We have measured the m(5007) magnitudes of 145 PNs and produced a statistically complete sample of 40 PNs in NGC 821. The resulting PN luminosity function (PNLF) was used to estimate a distance modulus of 31.4mag, equivalent to 19Mpc.
- ID:
- ivo://CDS.VizieR/J/ApJ/736/65
- Title:
- PNe in the Virgo elliptical galaxy NGC 4649
- Short Name:
- J/ApJ/736/65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using a slitless spectroscopy method with (1) the 8.2m Subaru telescope and its FOCAS Cassegrain spectrograph and (2) the ESO Very Large Telescope unit 1 (Antu) and its FORS2 Cassegrain spectrograph, we have detected 326 planetary nebulae (PNs) in the giant Virgo elliptical galaxy NGC 4649 (M60) and measured their radial velocities. After rejecting some PNs more likely to belong to the companion galaxy NGC 4647, we have built a catalog with kinematic information for 298 PNs in M60. Using these radial velocities, we have concluded that they support the presence of a dark matter halo around M60. Based on an isotropic, two-component Hernquist model, we estimate the dark matter halo mass within 3R_e_ to be 4x10^11^M_{sun}_, which is almost one-half of the total mass of about 10^12^M_{sun}_ within 3R_e_. This total mass is similar to that estimated from globular cluster, XMM-Newton, and Chandra observations. The dark matter becomes dominant outside. More detailed dynamical modeling of the PN data is being published in a companion paper. We have also measured the m(5007) magnitudes of many of these PNs and built a statistically complete sample of 218 PNs. The resulting PN luminosity function (PNLF) was used to estimate a distance modulus of 30.7+/-0.2mag, equivalent to 14+/-1Mpc. This confirms an earlier PNLF distance measurement based on a much smaller sample. The PNLF distance modulus remains smaller than the surface brightness fluctuation distance modulus by 0.4mag.
- ID:
- ivo://CDS.VizieR/J/MNRAS/498/6005
- Title:
- PN ETHOS 1 Bgri magnitudes & radial velocities
- Short Name:
- J/MNRAS/498/6005
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed study of the binary central star of the planetary nebula ETHOS 1 (PN G068.1+11.0). Simultaneous modelling of light and radial velocity curves reveals the binary to comprise a hot and massive pre-white-dwarf with an M-type main-sequence companion. A good fit to the observations was found with a companion that follows expected mass-temperature-radius relationships for low-mass stars, indicating that despite being highly irradiated it is consistent with not being significantly hotter or larger than a typical star of the same mass. Previous modelling indicated that ETHOS 1 may comprise the first case where the orbital plane of the central binary does not lie perpendicular to the nebular symmetry axis, at odds with the expectation that the common envelope is ejected in the orbital plane. We find no evidence for such a discrepancy, deriving a binary inclination in agreement with that of the nebula as determined by spatio-kinematic modelling. This makes ETHOS 1 the ninth post-common-envelope planetary nebula in which the binary orbital and nebular symmetry axes have been shown to be aligned, with as yet no known counter-examples. The probability of finding such a correlation by chance is now less than 0.00002%.
- ID:
- ivo://CDS.VizieR/J/A+A/642/A108
- Title:
- PN G283.7-05.1 BVRI and RV curves
- Short Name:
- J/A+A/642/A108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery and characterisation of the post-common-envelope central star system in the planetary nebula PN G283.7-05.1. Deep images taken as part of the POPIPlaN survey indicate that the nebula may possess a bipolar morphology similar to other post-common-envelope planetary nebulae. Simultaneous light and radial velocity curve modelling reveals the newly discovered binary system to comprise a highly-irradiated, M-type main-sequence star in a 5.9 hour orbit with a hot pre-white-dwarf. The nebular progenitor is found to have a particularly low mass of around 0.4M_{sun}_, making PN G283.7-05.1 one of only a handful of candidate planetary nebulae to be the product of a common-envelope event while still on the red giant branch. Beyond its low mass, the model temperature, surface gravity and luminosity are all found to be consistent with the observed stellar and nebular spectra through comparison with model atmospheres and photoionisation modelling. However, the high temperature (Teff~95kK) and high luminosity of the central star of the nebula are not consistent with post-RGB evolutionary tracks.
1226. PN Ou5 gri and RV curves
- ID:
- ivo://CDS.VizieR/J/MNRAS/510/3102
- Title:
- PN Ou5 gri and RV curves
- Short Name:
- J/MNRAS/510/3102
- Date:
- 19 Jan 2022 08:33:22
- Publisher:
- CDS
- Description:
- We present a detailed study of the stellar and orbital parameters of the post-common envelope binary central star of the planetary nebula Ou5. Low-resolution spectra obtained during the primary eclipse - to our knowledge the first isolated spectra of the companion to a post-common-envelope planetary nebula central star - were compared to catalogue spectra, indicating that the companion star is a late K- or early M-type dwarf. Simultaneous modelling of multi-band photometry and time-resolved radial velocity measurements was then used to independently determine the parameters of both stars as well as the orbital period and inclination. The modelling indicates that the companion star is low mass (~0.25M_{sun}_) and has a radius significantly larger than would be expected for its mass. Furthermore, the effective temperature and surface gravity of nebular progenitor, as derived by the modelling, do not lie on single-star post-AGB evolutionary tracks, instead being more consistent with a post-RGB evolution. However, an accurate determination of the component masses is challenging. This is principally due to the uncertainty on the locus of the spectral lines generated by the irradiation of the companion's atmosphere by the hot primary (used to derive companion star's radial velocities), as well as the lack of radial velocities of the primary.
- ID:
- ivo://CDS.VizieR/J/A+A/491/951
- Title:
- Positions and cross-references in Coma Ber
- Short Name:
- J/A+A/491/951
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Although several attempts were made to identify solar-type members on the main sequence of the nearby open cluster Coma Berenices (Mel 111), the population of the lower main sequence is still poorly known. We observed 46 new candidates to search for new members and monitored known spectroscopic-binary members to determine orbital parameters. We obtained a total of 903 radial-velocity measurements of 69 solar-type stars in the field of Mel 111 with the CORAVEL spectrovelocimeter over 20 years. Among the 35 stars from Trumpler's list, 23 are members according to their radial velocities and photometry. We were able to confirm the membership of only 8 stars among the 46 candidates observed. Six double-lined and ten single-lined spectroscopic binaries were discovered. Six only are members and an orbit was determined for them and for 4 double-lined non-members. The binary frequency is 22% (7/32). The cluster mean radial velocity is +0.01+/-0.08km/s based on 28 members. The lower main sequence of the Coma Berenices open cluster is still rather poorly populated. The cluster size may be much larger that usually accepted. Accordingly extensive programmes of precise proper motions, radial velocities and photometry should be undertaken to identify faint cluster members outside the cluster central area. If a significant population of faint members cannot be identified, Coma Ber could be a prominent example of dynamical evolution leading to star evaporation.
- ID:
- ivo://CDS.VizieR/J/AJ/126/762
- Title:
- Positions and space velocities for 2615 SGP stars
- Short Name:
- J/AJ/126/762
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectrophotometric data have been obtained with the 2dF spectrograph at Cerro Tololo Inter-American Observatory and with Hydra at the WIYN telescope for nearly 2000 A, F, and G stars toward the south Galactic pole. Using 1305 radial velocities, 2311 uvbyH{beta} photometric measurements, and 1621 Yale-San Juan SPM (Southern Proper Motion) absolute proper motions, peculiar velocities were derived to determine the galactic gravitational force K(z) perpendicular to the Galactic plane, first described by Oort (published in 1932).
- ID:
- ivo://CDS.VizieR/J/A+A/513/L7
- Title:
- Post common envelope binaries from SDSS. VIII
- Short Name:
- J/A+A/513/L7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a large survey of post common envelope binaries (PCEBs) among white dwarf/main sequence (WDMS) binaries from the SDSS that allows to determine the fraction of PCEBs as a function of secondary star mass and therewith to ultimately test the disrupted magnetic braking hypothesis. We obtained multiple spectroscopic observations spread over at least two nights of 589 WDMS binaries. Using mostly the NaI 8183.27,8194.81 absorption doublet we determined the corresponding radial velocities.
- ID:
- ivo://CDS.VizieR/J/ApJ/839/92
- Title:
- Praesepe members with K2 light curve data
- Short Name:
- J/ApJ/839/92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have Fourier-analyzed 941 K2 light curves (LCs) of likely members of Praesepe, measuring periods for 86% and increasing the number of rotation periods (P) by nearly a factor of four. The distribution of P versus (V-Ks), a mass proxy, has three different regimes: (V-Ks)<1.3, where the rotation rate rapidly slows as mass decreases; 1.3<(V-Ks)<4.5, where the rotation rate slows more gradually as mass decreases; and (V-Ks)>4.5, where the rotation rate rapidly increases as mass decreases. In this last regime, there is a bimodal distribution of periods, with few between ~2 and ~10 days. We interpret this to mean that once M stars start to slow down, they do so rapidly. The K2 period-color distribution in Praesepe (~790Myr) is much different than that in the Pleiades (~125Myr) for late F, G, K, and early-M stars; the overall distribution moves to longer periods and is better described by two line segments. For mid-M stars, the relationship has a similarly broad scatter and is steeper in Praesepe. The diversity of LCs and of periodogram types is similar in the two clusters; about a quarter of the periodic stars in both clusters have multiple significant periods. Multi- periodic stars dominate among the higher masses, starting at a bluer color in Praesepe ((V-Ks)~1.5) than in the Pleiades ((V-Ks)~2.6). In Praesepe, there are relatively more LCs that have two widely separated periods, {Delta}P>6days. Some of these could be examples of M star binaries where one star has spun down but the other has not.
