- ID:
- ivo://CDS.VizieR/J/MNRAS/504/3580
- Title:
- Fornax galaxy cluster NIR images & catalogs
- Short Name:
- J/MNRAS/504/3580
- Date:
- 06 Jan 2022 17:55:05
- Publisher:
- CDS
- Description:
- Ultra-compact dwarf galaxies (UCDs) were serendipitously discovered by spectroscopic surveys in the Fornax cluster 20 yr ago. Nowadays, it is commonly accepted that many bright UCDs are the nuclei of galaxies that have been stripped. However, this conclusion might be driven by biased samples of UCDs in high-density environments, on which most searches are based. With the deep optical images of the Fornax Deep Survey, combined with public near-infrared data, we revisit the UCD population of the Fornax cluster and search for UCD candidates, for the first time, systematically out to the virial radius of the galaxy cluster. Our search is complete down to magnitude m_g_=21mag or M_g_~-10.5mag at the distance of the Fornax cluster. The UCD candidates are identified and separated from foreground stars and background galaxies by their optical and near-infrared colours. This primarily utilizes the u-i/i-Ks diagram and a machine learning technique is employed to incorporate other colour combinations to reduce the number of contaminants. The newly identified candidates (44) in addition to the spectroscopically confirmed UCDs (61), increase the number of known Fornax UCD considerably (105). Almost all of the new UCD candidates are located outside the Fornax cluster core (360kpc), where all of the known UCDs were found. The distribution of UCDs within the Fornax cluster shows that a population of UCDs may form in low-density environments. This most likely challenges the current models of UCD formation.
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Search Results
4812. Fornax Globular 3
- ID:
- ivo://CDS.VizieR/J/AJ/114/1471
- Title:
- Fornax Globular 3
- Short Name:
- J/AJ/114/1471
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new B-V color-magnitude diagrams for Fornax globular cluster 3 and the surrounding field where our data reach one magnitude below the horizontal branch which is at V_HB_=21.28. After subtracting the field stars from the cluster CMD, we found no evidence for an intrinsic width of the red giant branch because the scatter is only slightly wider than the photometric errors. We determine that there is an intrinsic width to the horizontal branch because the scatter is larger than the photometric errors. After comparing our data with earlier photometry, we find 7 possible variable stars, both within and outside the instability strip, out of a total of 74 horizontal branch stars. We calculate the horizontal branch type of cluster 3 to be of intermediate color, -0.110+/-0.104, which when compared to Fornax cluster 1, having similar metallicity, suggests a second-parameter pair. Five carbon star candidates identified by Jorgensen & Jimenez (1997, Cat. <J/A+A/317/54>) are marked in the field-subtracted color-magnitude diagram. (c) 1997 American Astronomical Society.
4813. Fornax globular clusters
- ID:
- ivo://CDS.VizieR/J/A+A/657/A93
- Title:
- Fornax globular clusters
- Short Name:
- J/A+A/657/A93
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The Fornax cluster provides an unparalleled opportunity of investigating the formation and evolution of early-type galaxies in a dense environment in detail. We aim at kinematically characterising photometrically detected globular cluster (GC) candidates in the core of the cluster. We used VLT/VIMOS spectroscopic data from the FVSS survey in the Fornax cluster, covering one square degree around the central massive galaxy NGC 1399. We confirm a total of 777 GCs, almost doubling previously detected GCs, using the same dataset as was used before. Combined with previous literature radial velocity measurements of GCs in Fornax, we compile the most extensive spectroscopic GC sample of 2341 objects in this environment. We found that red GCs are mostly concentrated around major galaxies, while blue GCs are kinematically irregular and are widely spread throughout the core region of the cluster. The velocity dispersion profiles of blue and red GCs show a quite distinct behaviour. Blue GCs exhibit a sharp increase in the velocity dispersion profile from 250 to 400km/s within 5 arcminutes (~29kpc~1r_eff_ of NGC 1399) from the central galaxy. The velocity dispersion profile of red GCs follows a constant value between 200-300km/s until 8 arcminutes (~46kpc~1.6r_eff_, and then rises to 350km/s at 10 arcminutes (~58kpc~2r_eff_). Beyond 10 arcminutes and out to 40 arcminutes (~230kpc~8r_eff_), blue and red GCs show a constant velocity dispersion of 300+/-50km/s, indicating that both GC populations trace the cluster potential. We kinematically confirm and characterise the previously photometrically discovered overdensities of intra-cluster GCs. We found that these substructured intra-cluster regions in Fornax are dominated mostly by blue GCs.
- ID:
- ivo://CDS.VizieR/J/MNRAS/453/690
- Title:
- Fornax VST ATLAS catalogue
- Short Name:
- J/MNRAS/453/690
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a panoramic study of the Fornax dwarf spheroidal galaxy, using data obtained as part of the VLT Survey Telescope (VST) ATLAS Survey. The data presented here - a subset of the full survey - uniformly cover a region of 25deg^2^ centred on the galaxy, in g, r and i bands. This large area coverage reveals two key differences to previous studies of Fornax. First, data extending beyond the nominal tidal radius of the dwarf highlight the presence of a second distinct red giant branch population. This bluer red giant branch appears to be co-eval with the horizontal branch population. Secondly, a shell structure located approximately 1.4{deg} from the centre of Fornax is shown to be a mis-identified background overdensity of galaxies. This last result casts further doubt on the hypothesis that Fornax underwent a gas-rich merger in its relatively recent past.
- ID:
- ivo://CDS.VizieR/J/A+A/583/A115
- Title:
- FORS1 catalogue of stellar magnetic fields
- Short Name:
- J/A+A/583/A115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The FORS1 instrument of the ESO Very Large Telescope was used to obtain low resolution circular polarized spectra of nearly a thousand of different stars, with the aim of measuring their mean longitudinal magnetic fields. Magnetic fields were measured by different authors, and using different methods and software tools. A catalogue of FORS1 magnetic measurements would provide a valuable resource with which to better understand the strengths and limitations of this instrument and of similar low-dispersion, Cassegrain spectropolarimeters. However, FORS1 data reduction has been carried out by a number of different groups using a variety of reduction and analysis techniques. Both our understanding of the instrument and our data reduction techniques have improved over time. A full re-analysis of FORS1 archive data using a consistent and fully documented algorithm would optimise the accuracy and usefulness of a catalogue of field measurements. Based on ESO FORS pipeline, we have developed a semi-automatic procedure for magnetic field determinations, which includes self-consistent checks for field detection reliability. We have applied our procedure to the full content of circular spectropolarimetric measurements of the FORS1 archive. We have produced a catalogue of spectro-polarimetric observations and magnetic field measurements for 1400 observations of 850 different objects. The spectral type of each object has been accurately classified. We have also been able to test different methods for data reduction is a systematic way. The resulting catalogue has been used to produce an estimator for an upper limit to the uncertainty in a field strength measurement of an early type star as a function of the signal-to-noise ratio of the observation. While FORS1 is not necessarily an optimal instrument for the discovery of weak magnetic fields, it is very useful for the systematic study of larger fields, such as those found in Ap/Bp stars and in white dwarfs.
- ID:
- ivo://CDS.VizieR/J/A+A/440/61
- Title:
- FORS spectroscopy of HDFS galaxies
- Short Name:
- J/A+A/440/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present low resolution multi-object spectroscopy of an I-band magnitude limited (I_AB_~23-23.5) sample of galaxies located in an area centered on the Hubble Deep Field-South (HDFS). The observations were obtained using the Focal Reducer/low dispersion Spectrograph (FORS) on the ESO Very Large Telescope. Thirty-two primary spectroscopic targets in the HST-WFPC2 HDFS were supplemented with galaxies detected in the Infrared Space Observatory's survey of the HDFS and the ESO Imaging Deep Survey to comprise a sample of 100 galaxies for spectroscopic observations. Based on detections of several emission lines, such as [OII]3727, H{beta} and [OIII]5007, or of other spectroscopic features, we measured accurate redshifts for 50 objects in the central HDFS and flanking fields. The redshift range of the current sample of galaxies is 0.6-1.2, with a median redshift of 1.13 (at I~23.5 not corrected for completeness). The sample is dominated by starburst galaxies with only a small fraction of ellipticals (~10%). For the emission line objects, the extinction corrected [OII]3727 line strengths yield estimates of star formation rates in the range 0.5-30M_{sun}_/yr. We used the present data to derive the [OII]3727 luminosity function up to redshift of 1.2. When combined with [OII]3727 luminosity densities for the local and high redshift Universe, our results confirm the steep rise in the star formation rate (SFR) to z~1.3.
4817. Fossil galaxy groups
- ID:
- ivo://CDS.VizieR/J/AJ/137/3942
- Title:
- Fossil galaxy groups
- Short Name:
- J/AJ/137/3942
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use SDSS-DR4 photometric and spectroscopic data out to redshift z~0.1 combined with ROSAT All Sky Survey X-ray data to produce a sample of 25 fossil groups (FGs), defined as bound systems dominated by a single, luminous elliptical galaxy with extended X-ray emission. We examine possible biases introduced by varying the parameters used to define the sample, and the main pitfalls are also discussed.
- ID:
- ivo://CDS.VizieR/J/MNRAS/475/193
- Title:
- Foundation Supernova Survey first data release
- Short Name:
- J/MNRAS/475/193
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Foundation Supernova Survey aims to provide a large, high-fidelity, homogeneous, and precisely calibrated low-redshift Type Ia supernova (SN Ia) sample for cosmology. The calibration of the current low-redshift SN sample is the largest component of systematic uncertainties for SN cosmology, and new data are necessary to make progress. We present the motivation, survey design, observation strategy, implementation, and first results for the Foundation Supernova Survey. We are using the Pan-STARRS telescope to obtain photometry for up to 800 SNe Ia at z<~0.1. This strategy has several unique advantages: (1) the Pan-STARRS system is a superbly calibrated telescopic system, (2) Pan-STARRS has observed 3/4 of the sky in grizyP1 making future template observations unnecessary, (3) we have a well-tested data-reduction pipeline, and (4) we have observed ~3000 high-redshift SNe Ia on this system. Here, we present our initial sample of 225 SN Ia grizP1 light curves, of which 180 pass all criteria for inclusion in a cosmological sample. The Foundation Supernova Survey already contains more cosmologically useful SNe Ia than all other published low-redshift SN Ia samples combined. We expect that the systematic uncertainties for the Foundation Supernova Sample will be two to three times smaller than other low-redshift samples. We find that our cosmologically useful sample has an intrinsic scatter of 0.111mag, smaller than other low-redshift samples. We perform detailed simulations showing that simply replacing the current low-redshift SN Ia sample with an equally sized Foundation sample will improve the precision on the dark energy equation-of-state parameter by 35 per cent, and the dark energy figure of merit by 72 per cent.
- ID:
- ivo://CDS.VizieR/J/MNRAS/451/2735
- Title:
- Four close dSph XXM observations
- Short Name:
- J/MNRAS/451/2735
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the analysis of deep archival XMM-Newton observations towards the dwarf spheroidal galaxies Draco, Leo I, Ursa Major II (UMa II) and Ursa Minor (UMi) in the Milky Way neighbourhood. The X-ray source population is characterized and cross-correlated with available databases to infer their nature. We also investigate if intermediate-mass black holes are hosted in the centre of these galaxies. For Draco, we detect 96 high-energy sources, two of them possibly being local stars, while no evidence for any X-ray emitting central compact object is found. Towards the Leo I and UMa II fields of view, we reveal 116 and 49 X-ray sources, respectively. None of them correlates with the putative central black holes and only one is likely associated with a UMa II local source. The study of the UMi dwarf galaxy found 54 high-energy sources and a possible association with a source at the dwarf spheroidal galaxy centre. We put an upper limit on the luminosity of the central compact object of 4.02x10^33^erg/s. Furthermore, via the correlation with a radio source near the galactic centre, the putative black hole should have a mass of (2.76^+32.00^_-2.54_)x10^6^M_{sun}_ and be radiatively inefficient. This confirms a previous result obtained using Chandra data alone.
- ID:
- ivo://CDS.VizieR/J/A+A/650/A173
- Title:
- Four Herbig-Haro objects SOFIA/FIFI-LS images
- Short Name:
- J/A+A/650/A173
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We present SOFIA/FIFI-LS observations of three Class 0 and one Class I outflows (Cep E, HH 1, HH 212, and L1551 IRS5) in the far-infrared [OI]63um and [OI]145um transitions. Spectroscopic [OI]63um maps enable us to infer the spatial extent of warm (T~500-1200K), low-excitation atomic gas within these protostellar outflows. Our main goal is to determine mass-loss rates from the obtained [OI]63um maps and compare these with accretion rates from other studies. The far-infrared [OI]63um emission line is predicted to be the main coolant of dense, dissociative J-shocks caused by decelerated wind or jet shocks. If proper shock conditions prevail, the instantaneous mass-ejection rate is directly connected to the [OI]63um luminosity. In order to unravel evolutionary trends we analyse a set of 14 Class 0/I outflow sources that have been spatially resolved in the [OI]63um emission. We compare these data with a sample of 74 Class 0/I/II outflow sources that have been observed with Herschel (WISH, DIGIT, WILL, GASPS surveys) without spatially resolving the [OI]63um line.