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2562. NGC 3269 CO spectra
- ID:
- ivo://CDS.VizieR/J/A+A/645/A36
- Title:
- NGC 3269 CO spectra
- Short Name:
- J/A+A/645/A36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An intriguing silhouette of a small dust patch can be seen against the disk of the S0 galaxy NGC 3269 in the Antlia cluster in optical images. The images do not provide any clue as to whether the patch is a local Jupiter mass-scale cloudlet or a large extragalactic dust complex. We aim to resolve the nature of this object: is it a small Galactic cloudlet or an extragalactic dust complex? ALMA and APEX spectroscopy and Gemini GMOS long-slit spectroscopy were used to measure the velocity of the patch and the NGC 3269 disk radial velocity curve. A weak 16+/-2.5km/s wide ^12^CO (2-1) T_MB_ 19+/-2.5mK line in a 2.2" by 2.12" beam associated with the object was detected with ALMA. The observed heliocentric velocity, V_r,hel_=3878+/-5.0km/s, immediately establishes the extragalactic nature of the object. The patch velocity is consistent with the velocity of the nucleus of NGC 3269, but not with the radial velocity of the NGC 3269 disk of the galaxy at its position. The ~4" angular size of the patch corresponds to a linear size of ~1kpc at the galaxy's Hubble distance of 50.7Mpc. The mass estimated from the ^12^CO (2-1) emission is ~1.4x10^6^(d/50.7Mpc)^2^M_{sun}_, while the attenuation derived from the optical spectrum implies a dust mass of ~2.6x10^4^(d/50.7Mpc)^2^M_{sun}_. The derived attenuation ratio A'_B_/(A'_B_-A'_R_) of 1.6+/-0.11 is substantially lower than the corresponding value for the mean Milky Way extinction curve for point sources (2.3). We established the extragalactic nature of the patch, but its origin remains elusive. One possibility is that the dust patch is left over from the removal of interstellar matter in NGC 3269 through the interaction with its neighbour, NGC 3268.
- ID:
- ivo://CDS.VizieR/J/A+A/625/A76
- Title:
- NGC1052-DF2 VLT/MUSE datacubes
- Short Name:
- J/A+A/625/A76
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The so-called ultra-diffuse galaxy NGC 1052-DF2 was announced to be a galaxy lacking dark matter based on a spectroscopic study of its constituent globular clusters. Here we present the first spectroscopic analysis of the stellar body of this galaxy using the MUSE integral-field spectrograph at the (ESO) Very Large Telescope. The MUSE datacube simultaneously provides DF2's stellar velocity field and systemic velocities for seven globular clusters (GCs). We further discovered three planetary nebulae (PNe) that are likely part of this galaxy. While five of the clusters had velocities measured in the literature, we were able to confirm the membership of two more candidates through precise radial velocity measurements, which increases the measured specific frequency of GCs in DF2. The mean velocity of the diffuse stellar body, 1792.9^-1.8^_+1.4_km/s, is consistent with the mean globular cluster velocity.We detect a weak but significant velocity gradient within the stellar body, with a kinematic axis close to the photometric major axis, making it a prolate-like rotator. We estimate a velocity dispersion from the clusters and PNe of {sigma}_int_= 10.6^+3.9^_-2.3_km/s. The velocity dispersion DF2?(Re) for the stellar body within one effective radius is 10.8^-4.0^_+3.2_km/s. Considering various sources of systemic uncertainties, this central value varies between 5 and 13km/s, and we conservatively report a 95% confidence upper limit to the dispersion within one Re of 21km/s. We provide updated mass estimates based on these dispersions corresponding to the different distances to NGC 1052-DF2 that have been reported in the recent literature.
- ID:
- ivo://CDS.VizieR/J/MNRAS/461/4260
- Title:
- NGC1316 (Fornax A) g'r'i' photometry
- Short Name:
- J/MNRAS/461/4260
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents Gemini-gri' high-quality photometry for cluster candidates in the field of NGC 1316 (Fornax A) as part of a study that also includes GMOS spectroscopy. A preliminary discussion of the photometric data indicates the presence of four stellar cluster populations with distinctive features in terms of age, chemical abundance and spatial distribution. Two of them seem to be the usually old (metal poor and metal rich) populations typically found in elliptical galaxies. In turn, an intermediate-age (5 Gyr) globular cluster population is the dominant component of the sample (as reported by previous papers). We also find a younger cluster population with a tentative age of ~=1Gyr.
- ID:
- ivo://CDS.VizieR/J/A+A/641/A95
- Title:
- NGC 4104 g and r CFHT/Megacam images
- Short Name:
- J/A+A/641/A95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Groups are the most common association of galaxies in the Universe and they are found in different configuration states, such as loose, compact, and fossil groups. We studied the galaxy group MKW 4s, dominated by the giant early-type galaxy NGC 4104 at z=0.0282, with the aim of understanding the evolutionary stage of this group and to place it within the framework of the standard {Lambda}CDM cosmological scenario. We obtained deep optical data with CFHT/Megacam (g and r bands) and we applied both the galfit 2D image fitting program and the IRAF/ellipse 1D radial method to model the brightest group galaxy (BGG) and its extended stellar envelope. We also analysed the publicly available XMM-Newton and Chandra X-ray data. From N-body simulations of dry-mergers with different mass ratios of the infalling galaxy, we were able to constrain the dynamical stage of this system. Our results show a stellar shell system feature in NGC 4104 and an extended envelope that was reproduced by our numerical simulations of a collision with a satellite galaxy taking place about 4-6Gyr ago. The initial pair of galaxies had a mass ratio of at least 1:3. Taking into account the stellar envelope contribution to the total r band magnitude and the X-ray luminosity, MKW 4s falls into the category of a fossil group. Our results show that we are witnessing a rare case of a shell elliptical galaxy in a forming fossil group.
- ID:
- ivo://CDS.VizieR/J/A+A/654/A40
- Title:
- NGC1042 g and r deep final images
- Short Name:
- J/A+A/654/A40
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We present the first results of the LBT Imaging of Galaxy Haloes and Tidal Structures (LIGHTS) survey. LIGHTS is an ongoing observational campaign with the 2x8.4m Large Binocular Telescope (LBT) aiming to explore the stellar haloes and the low surface brightness population of satellites down to a depth of mu_V_~31mag/arcsec^2^ (3s in 10"x10" boxes) of nearby galaxies. We simultaneously collected deep imaging in the g and r Sloan filters using the Large Binocular Cameras (LBCs). The resulting images are 60 times (i.e. 4.5mag) deeper than those from the Sloan Digital Sky Survey (SDSS), and they have characteristics comparable (in depth and spatial resolution) to the ones expected from the future Legacy Survey of Space and Time (LSST). Here we show the first results of our pilot programme targeting NGC1042 (an M33 analogue at a distance of 13.5Mpc) and its surroundings. The depth of the images allowed us to detect an asymmetric stellar halo in the outskirts of this galaxy whose mass (1.4+/-0.4x10^8^M_{sun}_) is in agreement with the Lambda Cold Dark Matter (LambdaCDM) expectations. Additionally, we show that deep imaging from the LBT reveals low mass satellites (a few times 10^5^M_{sun}_) with very faint central surface brightness mu_V(0)_~27mag/arcsec^2^(i.e. similar to Local Group dwarf spheroidals, such as Andromeda XIV or Sextans, but at distances well beyond the local volume). The depth and spatial resolution provided by the LIGHTS survey open up a unique opportunity to explore the `missing satellites' problem in a large variety of galaxies beyond our Local Group down to masses where the difference between the theory and observation (if any) should be significant.
- ID:
- ivo://CDS.VizieR/J/A+A/659/A45
- Title:
- NGC4330 GHASP and PUMA datacubes
- Short Name:
- J/A+A/659/A45
- Date:
- 04 Mar 2022 00:48:25
- Publisher:
- CDS
- Description:
- Using the VESTIGE survey, a deep narrow-band H{alpha} imaging survey of the Virgo cluster carried on at the CFHT with MegaCam, we have discovered a long and diffuse tail of ionised gas in the edge-on late-type galaxy NGC4330. This peculiar feature witnesses an ongoing ram pressure stripping event able to remove the gas in the outer region of the disc. Tuned hydrodynamic simulations suggest that the ram pressure stripping event is occurring almost face-on, making NGC4330 the ideal candidate to study the effects of the perturbation in the direction perpendicular to the disc plane. We present here two new independent sets of Fabry-Perot observations (R~10000) with the purpose of understanding the effects of ram pressure stripping process on the kinematics of the ionised gas. Despite their limited sensitivity to the diffuse gas emission, the data allowed us to measure the velocity and the velocity dispersion fields over the galaxy disc and in several features at the edges or outside the stellar disc formed after the ram pressure stripping event. We have constructed the position-velocity diagrams and the rotation curves of the galaxy using three different techniques. The data show, consistent with the hydrodynamic simulations, that the galaxy has an inner solid-body rotation up to ~2.4kpc, with noncircular streaming motions outwards the disc and in the several external features formed during the interaction of the galaxy with the surrounding intracluster medium. The data also indicate a decrease of the rotational velocity of the gas with increasing distance from the galaxy disc along the tails, suggesting a gradual but not linear loss of angular momentum in the stripped gas. Consistent with a ram pressure stripping scenario, the i-band image shows a boxy shape at the southwest edge of the disc, where the stellar orbits might have been perturbed by the modification of the gravitational potential well of the galaxy due to the displacement of the gas in the z-direction.
- 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.
- 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.