- ID:
- ivo://CDS.VizieR/J/MNRAS/379/275
- Title:
- NGC 5033 1.4GHz radio emission
- Short Name:
- J/MNRAS/379/275
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new continuum VLA observations of the nearby Sy 1.5 galaxy NGC 5033, made at 4.9- and 8.4-GHz on 2003 April 8. Combined with VLA archival observations at 1.4- and 4.9-GHz made on 1993 August 7, 1999 August 29 and 1999 October 31, we sample the galaxy radio emission at scales ranging from the nuclear regions (<100pc) to the outer regions of the disc (~40kpc). The high-resolution VLA images show a corejet structure for the Sy 1.5 nucleus.
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- ID:
- ivo://CDS.VizieR/J/A+A/600/A6
- Title:
- NGC628 3.1GHz total intensity & polarised images
- Short Name:
- J/A+A/600/A6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Magnetic fields are essential to fully understand the interstellar medium (ISM) and its role in the disk-halo interface of galaxies is still poorly understood. Star formation is known to expel hot gas vertically into the halo and these outflows have important consequences for mean-field dynamo theory in that they can be efficient in removing magnetic helicity. We perform new observations of the nearby face-on spiral galaxy NGC 628 with the Karl G. Jansky Very Large Array (JVLA) at S-band and the Effelsberg 100-m telescope at frequencies of 2.6GHz and 8.35GHz. We obtain some of the most sensitive radio continuum images in both total and linearly polarised intensity of any external galaxy observed so far in addition to high-quality images of Faraday depth and polarisation angle from which we obtained evidence for drivers of magnetic turbulence in the disk-halo connection. Such drivers include a superbubble detected via a significant Faraday depth gradient coinciding with a HI hole. We observe an azimuthal periodic pattern in Faraday depth with a pattern wavelength of 3.7+/-0.1kpc, indicating Parker instabilities. The lack of a significant anti-correlation between Faraday depth and magnetic pitch angle indicates that these loops are vertical in nature with little helical twisting, unlike in IC 342. We find that the magnetic pitch angle is systematically larger than the morphological pitch angle of the polarisation arms which gives evidence for the action of a large-scale dynamo where the regular magnetic field is not coupled to the gas flow and obtains a significant radial component. We additionally discover a lone region of ordered magnetic field to the north of the galaxy with a high degree of polarisation and a small pitch angle, a feature that has not been observed in any other galaxy so far and is possibly caused by an asymmetric HI hole.
- ID:
- ivo://CDS.VizieR/J/A+A/612/A81
- Title:
- NGC 300 giant dust clouds
- Short Name:
- J/A+A/612/A81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use multi-band observations by the Herschel Space Observatory to study the dust emission properties of the nearby spiral galaxy NGC 300. We compile a first catalogue of the population of giant dust clouds (GDCs) in NGC 300, including temperature and mass estimates, and give an estimate of the total dust mass of the galaxy. We carried out source detection with the multiwavelength source extraction algorithm getsources. We calculated physical properties, including mass and temperature, of the GDCs from five-band Herschel PACS and SPIRE observations from 100-500{mu}m; the final size and mass estimates are based on the observations at 250{mu}m that have an effective spatial resolution of ~170pc. We correlated our final catalogue of GDCs to pre-existing catalogues of HII regions to infer the number of GDCs associated with high-mass star formation and determined the H{alpha} emission of the GDCs. Our final catalogue of GDCs includes 146 sources, 90 of which are associated with known HII regions. We find that the dust masses of the GDCs are completely dominated by the cold dust component and range from ~1.1x10^3^ to 1.4x10^4^M_{sun}_. The GDCs have effective temperatures of ~13-23K and show a distinct cold dust effective temperature gradient from the centre towards the outer parts of the stellar disk. We find that the population of GDCs in our catalogue constitutes ~16% of the total dust mass of NGC 300, which we estimate to be about 5.4x10^6^M_{sun}. At least about 87% of our GDCs have a high enough average dust mass surface density to provide sufficient shielding to harbour molecular clouds. We compare our results to previous pointed molecular gas observations in NGC 300 and results from other nearby galaxies and also conclude that it is very likely that most of our GDCs are associated with complexes of giant molecular clouds.
- ID:
- ivo://CDS.VizieR/J/ApJ/773/L36
- Title:
- NGC 5128 globular cluster abundances
- Short Name:
- J/ApJ/773/L36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present [Fe/H], ages, and Ca abundances for an initial sample of 10 globular clusters in NGC 5128 obtained from high-resolution, high signal-to-noise ratio echelle spectra of their integrated light. All abundances and ages are obtained using our original technique for high-resolution integrated light abundance analysis of globular clusters. The clusters have a range in [Fe/H] between -1.6 and -0.2. In this sample, the average [Ca/Fe] for clusters with [Fe/H]<-0.4 is +0.37+/-0.07, while the average [Ca/Fe] in our Milky Way (MW) and M31 GC samples is +0.29+/-0.09 and +0.24+/-0.10, respectively. This may imply a more rapid chemical enrichment history for NGC 5128 than for either the MW or M31. This sample provides the first quantitative picture of the chemical history of NGC 5128 that is directly comparable to what is available for the MW. Data presented here were obtained with the MIKE echelle spectrograph on the Magellan Clay Telescope.
- ID:
- ivo://CDS.VizieR/J/ApJ/671/1624
- Title:
- NGC 1533 globular cluster candidates
- Short Name:
- J/ApJ/671/1624
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use two-band imaging data from the Advanced Camera for Surveys onboard the Hubble Space Telescope for a detailed study of NGC 1533, an SB0 galaxy in the Dorado group surrounded by a ring of HI.
- ID:
- ivo://CDS.VizieR/J/A+A/543/A131
- Title:
- NGC1316 globular cluster candidates photometry
- Short Name:
- J/A+A/543/A131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of point-like sources around NGC 1316, which forms the photometric database for our paper. This catalogue basically is a selection from a larger photometric database. The selection criteria are specified in the paper. The catalog contains coordinates, R magnitudes with uncertainties, C-R colors and their uncertainties as well as "sharp" and "chi" values from DAOPHOT II. The coordinates are for identification purposes only. Depending on the position, deviations of up to 1 arcsec may occur. See the paper for validity limits of the photometric calibration, particularly for very red colors.
- ID:
- ivo://CDS.VizieR/J/MNRAS/452/2208
- Title:
- NGC 4473 globular clusters
- Short Name:
- J/MNRAS/452/2208
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- NGC 4473 is a so-called double sigma (2{sigma}) galaxy, i.e. a galaxy with rare, double peaks in its 2D stellar velocity dispersion. Here, we present the globular cluster (GC) kinematics in NGC 4473 out to ~10R_e_ (effective radii) using data from combined Hubble Space Telescope/Advanced Camera for Surveys and Subaru/Suprime-Cam imaging and Keck/Deep Imaging Multi-Object Spectrograph. We find that the 2{sigma} nature of NGC 4473 persists up to 3R_e_, though it becomes misaligned to the photometric major axis. We also observe a significant offset between the stellar and GC rotation amplitudes. This offset can be understood as a co-addition of counter-rotating stars producing little net stellar rotation. We identify a sharp radial transition in the GC kinematics at ~4R_e_ suggesting a well defined kinematically distinct halo. In the inner region (<4R_e_), the blue GCs rotate along the photometric major axis, but in an opposite direction to the galaxy stars and red GCs. In the outer region (>4R_e_), the red GCs rotate in an opposite direction compared to the inner region red GCs, along the photometric major axis, while the blue GCs rotate along an axis intermediate between the major and minor photometric axes. We also find a kinematically distinct population of very red GCs in the inner region with elevated rotation amplitude and velocity dispersion. The multiple kinematic components in NGC 4473 highlight the complex formation and evolutionary history of this 2{sigma} galaxy, as well as a distinct transition between the inner and outer components.
- ID:
- ivo://CDS.VizieR/J/ApJ/705/1533
- Title:
- NGC 5128 globular clusters
- Short Name:
- J/ApJ/705/1533
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An objective classification of the globular clusters (GCs) of NGC 5128 has been carried out by using a model-based approach of cluster analysis. The set of observable parameters includes structural parameters, spectroscopically determined Lick indices and radial velocities from the literature. The optimum set of parameters for this type of analysis is selected through a modified technique of principal component analysis, which differs from the classical one in the sense that it takes into consideration the effects of outliers present in the data. Then a mixture model based approach has been used to classify the GCs into groups. The efficiency of the techniques used is tested through the comparison of the misclassification probabilities with those obtained using the K-means clustering technique. On the basis of the above classification scheme three coherent groups of GCs have been found. We propose that the clusters of one group originated in the original cluster formation event that coincided with the formation of the elliptical galaxy, and that the clusters of the two other groups are of external origin, from tidally stripped dwarf galaxies on random orbits around NGC 5128 for one group, and from an accreted spiral galaxy for the other.
- ID:
- ivo://CDS.VizieR/J/AJ/133/2737
- Title:
- NGC 3610 globular clusters HST BVI photometry
- Short Name:
- J/AJ/133/2737
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Advanced Camera for Surveys on board the Hubble Space Telescope has been used to obtain deep, high-resolution images of the giant elliptical galaxy NGC 3610, a well-established remnant of a dissipative galaxy merger. These observations supersede previous, shallower observations that revealed the presence of a population of metal-rich globular clusters of intermediate age (~1.5-4Gyr). We detect a total of 580 cluster candidates, 46% more than from the previous WFPC2 images. The new photometry strengthens the significance of the previously found bimodality of the color distribution of clusters.
- ID:
- ivo://CDS.VizieR/J/AJ/140/2101
- Title:
- NGC 5128 globular clusters photometry
- Short Name:
- J/AJ/140/2101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new photometry for 323 of the globular clusters in NGC 5128 (Centaurus A), measured for the first time in the g'r'i'z' filter system. The color indices are calibrated directly to standard stars in the g'r'i'z' system and are used to establish the fiducial mean colors for the blue and red (low and high metallicity) globular cluster sequences. We also use previously published spectroscopically measured abundances to establish the conversion between the most metallicity-sensitive colors ((g'-r')_0_,(g'-i')_0_) and metallicity, [Fe/H].
