- ID:
- ivo://CDS.VizieR/J/A+AS/125/293
- Title:
- NGC 2366, NGC 2403 & NGC 4236 HK' photometry
- Short Name:
- J/A+AS/125/293
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Near Infrared H and K' surface photometry of the three nearby galaxies NGC 2366, NGC 2403 and NGC 4236, used as local calibrators of the Tully-Fisher relation, was obtained using the 256^2^ NICMOS3 IR array MAGIC attached to the 2.2 m telescope of Calar Alto. The present measurements are compared with the aperture photometry available in the literature. Surface brightness profiles and integrated magnitudes are given.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/611/A93
- Title:
- NGC3115 & NGC1399 VEGAS-SSS globular clusters
- Short Name:
- J/A+A/611/A93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze the globular cluster (GC) systems in two very different galaxies, NGC 3115 and NGC 1399. With the papers of this series, we aim at highlighting common and different properties in the GC systems in galaxies covering a wide range of parameter space. We compare the GCs in NGC 3115 and NGC 1399 as derived from the analysis of one square degree u-, g-, and i-band images taken with the VST telescope as part of the VST early-type galaxy survey (VEGAS) and Fornax deep survey (FDS). We selected GC candidates using as reference the morpho-photometric and color properties of confirmed GCs. The surface density maps of GCs in NGC 3115 reveal a morphology similar to the light profile of field stars; the same is true when blue and red GCs are taken separately. The GC maps for NGC 1399 are richer in structure and confirm the existence of an intra-cluster GC component. We confirm the presence of a spatial offset in the NGC 1399 GC centroid and find that the centroid of the GCs for NGC 3115 coincides well with the galaxy center. Both GC systems show unambiguous color bimodality in (g-i) and (u-i); the color-color relations of the two GC systems are slightly different with NGC 3115 appearing more linear than NGC 1399. The azimuthal average of the radial density profiles in both galaxies reveals a larger spatial extent for the total GCs population with respect to the galaxy surface brightness profile. For both galaxies, the red GCs have radial density profiles compatible with the galaxy light profile, while the radial profiles for blue GCs are shallower. As for the specific frequency of GCs, SN, we find it is a factor of two higher in NGC 1399 than for NGC 3115; this is mainly the result of extra blue GCs. By inspecting the radial behavior of the specific frequency, S_N_(<r), for the total, blue, and red GCs, we find notable similarities between the trends for red GCs in the two targets. In spite of extremely different host environments, the red GCs in both cases appear closely linked to the light distribution of field stars. Blue GCs extend to larger galactocentric scales than red GCs, marking a significant difference between the two galaxies: the blue/red GCs and field stellar components of NGC 3115 appear well thermalized with each other and the blue GCs in NGC 1399 appear to fade into an unrelaxed intra-cluster GC population.
2533. NGC 3516 optical flare
- ID:
- ivo://CDS.VizieR/J/A+A/638/A13
- Title:
- NGC 3516 optical flare
- Short Name:
- J/A+A/638/A13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observations from the short-term intensive optical campaign (from September 2019 to January 2020) of the changing-look Seyfert NGC 3516. This active galactic nucleus is known to have strong optical variability and has changed its type in the past. It has been in the low-activity state in the optical since 2013, with some rebrightening from the end of 2015 to the beginning of 2016, after which it remained dormant. We aim to study the photometric and spectral variability of NGC 3516 from the new observations in U- and B-bands and examine the profiles of the optical broad emission lines in order to demonstrate that this object may be entering a new state of activity. NGC 3516 has been monitored intensively for the past 4 months with an automated telescope in U and B filters, enabling accurate photometry of 0.01 precision. Spectral observations were triggered when an increase in brightness was spotted. We support our analysis of past-episodes of violent variability with the UV and X-ray long-term light curves constructed from the archival Swift/UVOT and Swift/XRT data. An increase of the photometric magnitude is seen in both U and B filters to a maximum amplitude of 0.25mag and 0.11mag, respectively. During the flare, we observe stronger forbidden high-ionization iron lines ([FeVII] and [FeX]) than reported before, as well as the complex broad H{alpha} and H{beta} lines. This is especially seen in H{alpha}, which appears to be double-peaked. It seems that a very broad component of ~10000km/s in width in the Balmer lines is appearing. The trends in the optical, UV, and X-ray light curves are similar, with the amplitudes of variability being significantly larger in the case of UV and X-ray bands. The increase of the continuum emission, the variability of the coronal lines, and the very broad component in the Balmer lines may indicate that the AGN of NGC 3516 is finally leaving the low-activity state in which it has been for the last ~3 years.
- ID:
- ivo://CDS.VizieR/J/A+A/539/A11
- Title:
- NGC 1316/1317 planetary nebula kinematics
- Short Name:
- J/A+A/539/A11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present positions and velocities for 796 planetary nebulae (PNe) in the Fornax Brightest Cluster Galaxy NGC 1316 (Fornax A). The planetary nebulae and existing kinematics are used to explore the rotation of this merger remnant and constrain dynamical models. Using FORS2 on the VLT, the PN velocities were measured using a counter-dispersed slitless-spectroscopy technique that produced the largest-to-date sample outside of the Local Group. Spherical, non-rotating, constant-anisotropy Jeans models were con- strained by observations of the planetary nebulae and existing integrated light spectra.
- ID:
- ivo://CDS.VizieR/J/A+A/623/A33
- Title:
- NGC 4666 polarization maps
- Short Name:
- J/A+A/623/A33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The observation of total and linearly polarized synchrotron radiation of spiral galaxies in the radio continuum reveals the distribution and structure of their magnetic fields. By observing these, information about the proposed dynamo processes that preserve the large-scale magnetic fields in spiral galaxies can be gained. Additionally, by analyzing the synchrotron intensity, the transport processes of cosmic rays into the halo of edge-on spiral galaxies can be investigated. We analyze the magnetic field geometry and the transport processes of the cosmic rays of the edge-on spiral starburst galaxy NGC 4666 from CHANG-ES radio data in two frequencies; 6 GHz (C-band) and 1.5 GHz (L-band). Supplementary X-ray data are used to investigate the hot gas in NGC 4666. We determine the radio scale heights of total power emission at both frequencies for this galaxy. We show the magnetic field orientations derived from the polarization data. Using rotation measure (RM) synthesis we further study the behavior of the RM values along the disk in C-band to investigate the large-scale magnetic-field pattern. We use the revised equipartition formula to calculate a map of the magnetic field strength. Furthermore, we model the processes of cosmic-ray transport into the halo with the 1D SPINNAKER model. The extended radio halo of NGC 4666 is box-shaped and is probably produced by the previously observed supernova-driven superwind. This is supported by our finding of an advective cosmic-ray transport such as that expected for a galactic wind. The scaleheight analysis revealed an asymmetric halo above and below the disk as well as between the two sides of the major axis. A central point source as well as a bubble structure is seen in the radio data for the first time. Our X-ray data show a box-shaped hot halo around NGC 4666 and furthermore confirm the AGN nature of the central source. NGC 4666 has a large-scale X-shaped magnetic field in the halo, as has been observed in other edge-on galaxies. The analysis furthermore revealed that the disk of NGC 4666 shows hints of field reversals along its radius, which is the first detection of this phenomenon in an external galaxy.
- ID:
- ivo://CDS.VizieR/J/A+A/314/43
- Title:
- NGC 5548 Profile variability
- Short Name:
- J/A+A/314/43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Optical emission line intensities of the variable Seyfert 1 galaxy NGC 5548 are presented.
- ID:
- ivo://CDS.VizieR/J/A+A/632/A13
- Title:
- NGC 4013 radio and polarization maps
- Short Name:
- J/A+A/632/A13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From the Continuum HAloes in Nearby Galaxies - an EVLA Survey (CHANG-ES) radio continuum data from the Karl G. Jansky Very Large Array (VLA), observed in two frequency bands, 6GHz (C-band) and 1.5GHz (L-band), we present the radio maps, including polarization of the edge-on spiral galaxy NGC 4013. Supplemantary X-ray data are also presented here. The central point source of NGC 4013 dominates the radio continuum emission in both CHANG-ES bands. Complementary X-ray data from Chandra show one dominant point source in the central part. The XMM-Newton spectrum shows hard X-rays, but no clear AGN classification is possible at this time. The radio continuum halo of NGC 4013 in C-band is rather small, while the low-frequency LOFAR data reveal a large halo. The scale height analysis shows that Gaussian fits better represent the intensity profiles than do exponential fits. The frequency dependence gives clear preference to diffusive CRE transport. The radio halo of NGC 4013 is relatively faint. Diffusion is the dominating transport process up to heights of 1-2kpc. The polarization data reveal plane-parallel, regular magnetic fields within the entire disk and vertical halo components indicating the presence of an axisymmetric field having a radial component pointing outwards. The mean magnetic field strength of the disk of NGC 4013 of 6.6{mu}G is rather small. Large-scale vertical fields are observed in the halo out to heights of about 6kpc. The interaction and the low star formation rate (SFR) across the disk of NGC 4013 probably influence the appearance of its radio continuum halo and are correlated with the low total magnetic field strength. Several observable quantities give consistent evidence that the CR transport in the halo of NGC 4013 is diffusive: the frequency dependence of the synchrotron scale height, the disk/halo flux density ratio, the vertical profile of the synchrotron spectral index, the small propagation speed measured modeled with spinnaker, and the low temperature of the X-ray emitting hot gas.
- ID:
- ivo://CDS.VizieR/J/A+A/639/A111
- Title:
- NGC 4217 radio and polarization maps
- Short Name:
- J/A+A/639/A111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the radio continuum halo, the magnetic field, and the transport processes of the CRs of the edge-on spiral galaxy NGC 4217 using Continuum HAlos in Nearby Galaxies - an Evla Survey (CHANG-ES) radio data at two frequencies, 6GHz (C-band) and 1.5GHz (L-band), and supplemental LOFAR data of this galaxy at 150MHz. With additional X-ray Chandra data, we study the connection of radio features to the diffuse hot gas around NGC 4217. NGC 4217 shows a large-scale X-shaped magnetic field structure, covering a major part of the galaxy with a mean total magnetic field strength in the disk of 9G. From the analysis of the rotation measure map at C-band, we found that the direction of the disk magnetic field is pointing inward. A helical outflow structure is furthermore present in the northwestern part of the galaxy, which is extended nearly 7 kpc into the halo. More polarized emission is observed on the approaching side of the galaxy, indicating that Faraday depolarization has to be considered at C-band. With a simplified galaxy disk model, we are able to explain the finding of higher polarized intensity on the approaching side. We generalize the model to predict that roughly 75% of edge-on spiral galaxies will show higher polarized intensity on the approaching side. Many loop and shell structures are found throughout the galaxy in total intensity at C-band. One structure, a symmetric off-center (to the southwest of the disk) superbubble-like structure is prominent in total and polarized intensity, as well as in Halpha and optical dust filaments. This is at a location where a second peak of total intensity (to the southwest of the disk) is observed, making this superbubble-like structure a possible result of a concentrated star formation region in the disk. The X-ray diffuse emission shows similarities to the polarized diffuse emission of NGC 4217. The flux density extension of the radio continuum halo increases toward lower frequencies. While the total flux density of the disk and halo are comparable at C-band, the contribution of the disk flux density decreases toward LOFAR to 18% of the total flux density. Dumbbell-shaped structures are present at C-band and at the LOFAR frequency. Total intensity profiles at the two CHANG-ES bands and the LOFAR frequency show a clear two-component behavior and were fit best with a two-component exponential fit. The halo scale heights are 1.10+/-0.04kpc, 1.43+/-0.09kpc, and 1.55+/-0.04kpc in C-band, L-band, and 150MHz, respectively. The frequency dependence of these scale heights between C-band and L-band suggests advection to be the main transport process. The 1D CRE transport modeling shows that advection appears to be more important than diffusion.
2539. NGC 352 R-band image
- ID:
- ivo://CDS.VizieR/J/A+A/647/A20
- Title:
- NGC 352 R-band image
- Short Name:
- J/A+A/647/A20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper is a contribution to the discussion about whether the X/peanut component is part of the bar, or the bar itself. Our goal is to present a clear-cut case of a barred-spiral galaxy in which all structural components (i.e. the thick and thin part of the bar and the spiral arms) can be observed in its image and their dimensions directly measured there. We obtained deep images of the nearby galaxy NGC 352, which has an ideal inclination allowing us to observe all of the parts that compose its morphology, estimate their relative sizes, and determine the topology of the luminous matter of this galaxy. We successfully compare our findings with the existence and the relative dimensions of the corresponding components encountered in the disc of a GADGET N-body model. NGC 352 is a barred spiral galaxy with a bar of about 13 kpc radius. Its bar has a central thick part that extends up to a distance about 5kpc from the centre of the galaxy along its major axis, while its thickness reaches a height of 3.8kpc. Thus, the thick part of the bar occupies the central part of the bar component, and its length is about 40% of that of the thin bar. The branches of the X-feature are characterised by the presence of 'hooks' at their extremities. The profile along the major axis of the bar is characterised by the presence of 'shoulders', the end of which is associated with local surface brightness enhancements on the equatorial plane. A central disc with a spiral-like feature embedded in it dominates in the innermost 1.7kpc. NGC 352 offers a case in which we directly observe that the X/peanut component is unambiguously part of the bar. This boxy structure is neither a separate bulge component nor the bar itself. The relative extent of the peanut with respect to the bar is well inside the range predicted in the majority of the simulated N-body bars. The hooks of the X-feature and the local surface brightness enhancements on the equatorial plane have their counterparts in surface density features of models based on the orbital theory, as well as of models based on response calculations and of fully selfconsistent N-body calculations.
- ID:
- ivo://CDS.VizieR/J/A+A/597/A85
- Title:
- NGC3627S and NGC3627N CO(1-0) data cubes
- Short Name:
- J/A+A/597/A85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To gain insight into the expected gas dynamics at the interface of the Galactic bar and spiral arms in our own MilkyWay galaxy, we examine as an extragalactic counterpart the evidence for multiple distinct velocity components in the cold, dense molecular gas populating a comparable region at the end of the bar in the nearby galaxy NGC 3627. We assemble a high resolution view of molecular gas kinematics traced by CO(2-1) emission and extract line-of-sight velocity profiles from regions of high and low gas velocity dispersion. The high velocity dispersions arise with often double-peaked or multiple line-profiles. We compare the centroids of the different velocity components to expectations based on orbital dynamics in the presence of bar and spiral potential perturbations. A model of the region as the interface of two gas-populated orbits families supporting the bar and the independently rotating spiral arms provides an overall good match to the data. An extent of the bar to the corotation radius of the galaxy is favored. Using NGC 3627 as an extragalactic example, we expect situations like this to favor strong star formation events such as observed in our own Milky Way since gas can pile up at the crossings between the orbit families. The relative motions of the material following these orbits is likely even more important for the build up of high density in the region. The surface densities in NGC 3627 are also so high that shear at the bar end is unlikely to significantly weaken the star formation activity. We speculate that scenarios in which the bar and spiral rotate at two different pattern speeds may be the most favorable for intense star formation at such interfaces.
