Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/399/813
- Title:
- Multiple merging events in Abell 521
- Short Name:
- J/A+A/399/813
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed spatial and dynamical analysis of the central ~2.2Mpc(Ho=75km/s/Mpc) region of the galaxy cluster Abell 521 (z=0.247), based on 238 spectra (of which 191 new measurements) obtained at the 3.6m Telescope of the European Southern Observatory and at the Canada-France-Hawaii Telescope. From the analysis of the 125 galaxies that are confirmed members of the cluster, we derive a location ("mean" velocity) of C_BI_=74019^{+112}^_{-125}_km/s and detect a complex velocity distribution with high velocity scale ("dispersion", S_BI_=1325^{+145}^_{-100}_km/s), but clear departure from a single Gaussian component. When excluding a possible background group of four galaxies, the velocity dispersion remains still large (~1200 km/s).
- ID:
- ivo://CDS.VizieR/J/ApJ/852/108
- Title:
- Multiwavelength obs. of gamma-ray NOVA Sco 2012
- Short Name:
- J/ApJ/852/108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- It has recently been discovered that some, if not all, classical novae emit GeV gamma-rays during outburst, but the mechanisms involved in the production of gamma-rays are still not well understood. We present here a comprehensive multiwavelength data set-from radio to X-rays-for the most gamma-ray-luminous classical nova to date, V1324 Sco. Using this data set, we show that V1324 Sco is a canonical dusty FeII-type nova, with a maximum ejecta velocity of 2600km/s and an ejecta mass of a few x10^-5^M_{sun}_. There is also evidence for complex shock interactions, including a double-peaked radio light curve which shows high brightness temperatures at early times. To explore why V1324 Sco was so gamma-ray luminous, we present a model of the nova ejecta featuring strong internal shocks and find that higher gamma-ray luminosities result from higher ejecta velocities and/or mass-loss rates. Comparison of V1324 Sco with other gamma-ray-detected novae does not show clear signatures of either, and we conclude that a larger sample of similarly well-observed novae is needed to understand the origin and variation of gamma-rays in novae.
- ID:
- ivo://CDS.VizieR/J/A+A/545/A97
- Title:
- 0.8-6{mu}m calibrated spectrum of 55 Cnc
- Short Name:
- J/A+A/545/A97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ACME Spectra project provides absolutely calibrated, mostly empirical spectra of exoplanet host stars for use in analysis of the stars and their planets. Spectra are obtained from ground-based telescopes and are tied directly to calibrated ground- and space-based photometry. The spectra remain only "mostly" empirical because of telluric absorption, but interpolation of stellar models over the gaps in wavelength coverage provides continuous stellar spectra. Among other uses, the spectra are suitable for precisely converting observed secondary eclipses (occultations) into absolute flux units with minimal recourse to models. In this paper, I introduce ACME's methods and present a calibrated spectrum of the nearby, super-Earth hosting star 55 Cancri that spans the range from 0.81-5.05um.
- ID:
- ivo://CDS.VizieR/J/ApJ/843/31
- Title:
- MUSCLES Treasury Survey. IV. M dwarf UV fluxes
- Short Name:
- J/ApJ/843/31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Characterizing the UV spectral energy distribution (SED) of an exoplanet host star is critically important for assessing its planet's potential habitability, particularly for M dwarfs, as they are prime targets for current and near-term exoplanet characterization efforts and atmospheric models predict that their UV radiation can produce photochemistry on habitable zone planets different from that on Earth. To derive ground-based proxies for UV emission for use when Hubble Space Telescope (HST) observations are unavailable, we have assembled a sample of 15 early to mid-M dwarfs observed by HST and compared their nonsimultaneous UV and optical spectra. We find that the equivalent width of the chromospheric Ca II K line at 3933{AA}, when corrected for spectral type, can be used to estimate the stellar surface flux in ultraviolet emission lines, including HI Ly{alpha}. In addition, we address another potential driver of habitability: energetic particle fluxes associated with flares. We present a new technique for estimating soft X-ray and >10MeV proton flux during far-UV emission line flares (Si IV and He II) by assuming solar-like energy partitions. We analyze several flares from the M4 dwarf GJ 876 observed with HST and Chandra as part of the MUSCLES Treasury Survey and find that habitable zone planets orbiting GJ 876 are impacted by large Carrington-like flares with peak soft X-ray fluxes >=10^-3^W/m^2^ and possible proton fluxes ~10^2^-10^3^pfu, approximately four orders of magnitude more frequently than modern-day Earth.
- ID:
- ivo://CDS.VizieR/J/MNRAS/473/663
- Title:
- MUSE and HFFs Photometry of A2744
- Short Name:
- J/MNRAS/473/663
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of Multi Unit Spectroscopic Explorer (MUSE) observations obtained on the massive Frontier Fields (FFs) cluster A2744. This new data set covers the entire multiply imaged region around the cluster core. The combined catalogue consists of 514 spectroscopic redshifts (with 414 new identifications). We use this redshift information to perform a strong-lensing analysis revising multiple images previously found in the deep FF images, and add three new MUSE-detected multiply imaged systems with no obvious Hubble Space Telescope counterpart. The combined strong-lensing constraints include a total of 60 systems producing 188 images altogether, out of which 29 systems and 83 images are spectroscopically confirmed, making A2744 one of the most well-constrained clusters to date. Thanks to the large amount of spectroscopic redshifts, we model the influence of substructures at larger radii, using a parametrization including two cluster-scale components in the cluster core and several group scale in the outskirts. The resulting model accurately reproduces all the spectroscopic multiple systems, reaching an rms of 0.67-arcsec in the image plane. The large number of MUSE spectroscopic redshifts gives us a robust model, which we estimate reduces the systematic uncertainty on the 2D mass distribution by up to ~2.5 times the statistical uncertainty in the cluster core. In addition, from a combination of the parametrization and the set of constraints, we estimate the relative systematic uncertainty to be up to 9 per cent at 200kpc.
- ID:
- ivo://CDS.VizieR/J/A+A/654/A80
- Title:
- MUSE Catalog of UV emission line measurement
- Short Name:
- J/A+A/654/A80
- Date:
- 02 Feb 2022 10:08:10
- Publisher:
- CDS
- Description:
- Rest-frame ultraviolet (UV) emission lines probe electron densities, gas-phase abundances, metallicities, and ionization parameters of the emitting star-forming galaxies and their environments. The strongest main UV emission line, Ly{alpha}, has been instrumental in advancing the general knowledge of galaxy formation in the early universe. However, observing Ly{alpha} emission becomes increasingly challenging at z>~6 when the neutral hydrogen fraction of the circumgalactic and intergalactic media increases. Secondary weaker UV emission lines provide important alternative methods for studying galaxy properties at high redshift. We present a large sample of rest-frame UV emission line sources at intermediate redshift for calibrating and exploring the connection between secondary UV lines and the emitting galaxies' physical properties and their Ly{alpha} emission. The sample of 2052 emission line sources with 1.5<z<6.4 was collected from integral field data from the MUSE-Wide and MUSE-Deep surveys taken as part of Guaranteed Time Observations. The objects were selected through untargeted source detection (i.e., no preselection of sources as in dedicated spectroscopic campaigns) in the three-dimensional MUSE data cubes. We searched optimally extracted one-dimensional spectra of the full sample for UV emission features via emission line template matching, resulting in a sample of more than 100 rest-frame UV emission line detections. We show that the detection efficiency of (non-Ly{alpha}) UV emission lines increases with survey depth, and that the emission line strength of HeII {lambda}1640AA, [OIII] {lambda}1661 + OIII] {lambda}1666, and [SiIII] {lambda}1883 + SiIII] {lambda}1892 correlate with the strength of [CIII] {lambda}1907 + CIII] {lambda}1909. The rest-frame equivalent width (EW0 ) of [CIII] {lambda}1907+CIII] {lambda}1909 is found to be roughly 0.22+/-0.18 of EW0 (Ly{alpha}). We measured the velocity offsets of resonant emission lines with respect to systemic tracers. For CIV {lambda}1548 + CIV {lambda}1551 we find that {DELTA}v_CIV_<~250km/s, whereas {nu}v_Ly{alpha}_ falls in the range of 250-500km/s which is in agreement with previous results from the literature. The electron density ne measured from [SiIII] {lambda}1883 + SiIII] {lambda}1892 and [CIII] {lambda}1907 + CIII] {lambda}1909 line flux ratios is generally <10^5^cm^-3^ and the gas-phase abundance is below solar at 12+log10(O/H)~=8. Lastly, we used "PhotoIonization Model Probability Density Functions" to infer physical parameters of the full sample and individual systems based on photoionization model parameter grids and observational constraints from our UV emission line searches. This reveals that the UV line emitters generally have ionization parameter log10(U) ~= -2.5 and metal mass fractions that scatter around Z~=10-2, that is Z~=0.66Z_{sun}_. Value-added catalogs of the full sample of MUSE objects studied in this work (this catalog) and a collection of UV line emitters from the literature are provided with this paper.
1708. MUSE datacube of He 2-10
- ID:
- ivo://CDS.VizieR/J/A+A/604/A101
- Title:
- MUSE datacube of He 2-10
- Short Name:
- J/A+A/604/A101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the physical and dynamical properties of the ionized gas in the prototypical HII galaxy Henize 2-10 using MUSE integral field spectroscopy. The large-scale dynamics are dominated by extended outflowing bubbles that are probably the result of massive gas ejection from the central star forming regions. We derived a mass outflow rate dM_out_/dt~0.30M_{sun}_/yr, corresponding to mass loading factor {eta}~0.4, in the range of similar measurements in local LIRGs. Such a massive outflow has a total kinetic energy that is sustainable by the stellar winds and supernova remnants expected in the galaxy. We studied the dust extinction, electron density, and ionization conditions all across the galaxy with a classical emission line diagnostic, confirming the extreme nature of the highly star forming knots in the core of the galaxy, which show high density and high ionization parameters. We measured the gas-phase metallicity in the galaxy, taking the strong variation of the ionization parameter into account, and found that the external parts of the galaxy have abundances as low as 12+log(O/H)~8.3, while the central star forming knots are highly enriched with super solar metallicity. We found no sign of AGN ionization in the galaxy, despite the recent claim of the presence of a supermassive active black hole in the core of He 2-10. We therefore reanalyzed the X-ray data that were used to propose the presence of the AGN, but we concluded that the observed X-ray emission can be better explained with sources of a different nature, such as a supernova remnant.
- ID:
- ivo://CDS.VizieR/J/A+A/644/A15
- Title:
- MUSE data for MR 2251-178 and PG 1126-041
- Short Name:
- J/A+A/644/A15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use MUSE adaptive optics (AO) data in Narrow Field Mode to study the properties of the ionised gas in MR 2251-178 and PG 1126-041, two nearby (z~0.06) bright quasars hosting sub-pc scale Ultra Fast Outflows (UFOs) detected in the X-ray band. We decompose the optical emission from diffuse gas into a low- and a high-velocity components. The former is characterised by a clean, regular velocity field and a low (~80 km/s) velocity dispersion. It traces regularly rotating gas in PG 1126-041, while in MR 2251-178 it is possibly associated to tidal debris from a recent merger or flyby. The other component is found to be extended up to a few kpc from the nuclei, and shows a high (~800km/s) velocity dispersion and a blue-shifted mean velocity, as expected from AGN-driven outflows. We estimate mass outflow rates up to a few Mo/yr and kinetic efficiencies between 0.1-0.4 per cent, in line with those of galaxies hosting AGNs of similar luminosity. The momentum rates of these ionised outflows are comparable to those measured for the UFOs at sub-pc scales, consistent with a momentum-driven wind propagation. Pure energy-driven winds are excluded unless about 100x additional momentum is locked in massive molecular winds. By comparing the outflow properties of our sources with those of a small sample of well-studied QSOs hosting UFOs from the literature, we find that winds seem to systematically lie either in a momentum-driven or in an energy-driven regime, indicating that these two theoretical models bracket very well the physics of AGN-driven winds.
1710. MUSE 3D view of HDF-S
- ID:
- ivo://CDS.VizieR/J/A+A/575/A75
- Title:
- MUSE 3D view of HDF-S
- Short Name:
- J/A+A/575/A75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We observed Hubble Deep Field South with the new panoramic integral-field spectrograph MUSE that we built and have just commissioned at the VLT. The data cube resulting from 27h of integration covers one arcmin^2^ field of view at an unprecedented depth with a 1{sigma} emission-line surface brightness limit of 1x10^-19^erg/s/cm2/arcsec2, and contains ~90000 spectra. We present the combined and calibrated data cube, and we performed a first-pass analysis of the sources detected in the Hubble Deep Field South imaging. We measured the redshifts of 189 sources up to a magnitude I_814_=29.5, increasing the number of known spectroscopic redshifts in this field by more than an order of magnitude. We also discovered 26 Ly{alpha} emitting galaxies that are not detected in the HST WFPC2 deep broad-band images. The intermediate spectral resolution of 2.3{AA} allows us to separate resolved asymmetric Ly{alpha} emitters, [OII]3727 emitters, and [CIII]1908 emitters, and the broad instantaneous wavelength range of 4500{AA} helps to identify single emission lines, such as [OIII]5007, H{beta}, and H{alpha}, over a very wide redshift range. We also show how the three-dimensional information of MUSE helps to resolve sources that are confused at ground-based image quality. Overall, secure identifications are provided for 83% of the 227 emission line sources detected in the MUSE data cube and for 32% of the 586 sources identified in the HST catalogue. The overall redshift distribution is fairly flat to z=6.3, with a reduction between z=1.5 to 2.9, in the well-known redshift desert. The field of view of MUSE also allowed us to detect 17 groups within the field. We checked that the number counts of [OII]3727 and Ly{alpha} emitters are roughly consistent with predictions from the literature. Using two examples, we demonstrate that MUSE is able to provide exquisite spatially resolved spectroscopic information on the intermediate-redshift galaxies present in the field. This unique data set can be used for a wide range of follow-up studies. We release the data cube, the associated products, and the source catalogue with redshifts, spectra, and emission-line fluxes.
![Data in this service is licensed under the `Creative Commons Attribution 4.0 License <http://creativecommons.org/licenses/by/4.0/>`_ .. image:: /static/img/ccby.png :alt: [CC-BY]](/registry-search/?f%5Brights_facet%5D%5B%5D=Data+in+this+service+is+licensed+under+the+%60Creative+Commons+Attribution+4.0+License+%3Chttp%3A%2F%2Fcreativecommons.org%2Flicenses%2Fby%2F4.0%2F%3E%60_%0A%0A..+image%3A%3A+%2Fstatic%2Fimg%2Fccby.png%0A+++%3Aalt%3A+%5BCC-BY%5D%0A%0A&f%5Bsubject_facet_lc%5D%5B%5D=spectroscopy){kind=link}