- ID:
- ivo://CDS.VizieR/J/ApJ/819/53
- Title:
- Magellan/M2FS spectroscopy of Tucana 2 and Grus 1
- Short Name:
- J/ApJ/819/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from spectroscopic observations with the Michigan/Magellan Fiber System (M2FS) of 147 stellar targets along the line of sight to the newly discovered "ultrafaint" stellar systems Tucana 2 (Tuc 2) and Grus 1 (Gru 1). Based on simultaneous estimates of line of sight velocity and stellar-atmospheric parameters, we identify 8 and 7 stars as probable members of Tuc 2 and and Gru 1, respectively. Our sample for Tuc 2 is sufficient to resolve an internal velocity dispersion of 8.6^+4.4^_-2.7_km/s about a mean of -129.1+/-3.5km/s (solar rest frame), and to estimate a mean metallicity of [Fe/H]=-2.23^+0.18^_-0.12_. These results place Tuc 2 on chemodynamical scaling relations followed by dwarf galaxies, suggesting a dominant dark matter component with dynamical mass 2.7^+3.1^_-1.3_x10^6^M_{sun}_ enclosed within the central ~160pc, and dynamical mass-to-light ratio 1913^+2234^_-950_M_{sun}_/L_{nu},{sun}_. For Gru 1 we estimate a mean velocity of -140.5^+2.4^_-1.6_km/s and a mean metallicity of [Fe/H]=-1.42^+0.55^_-0.42_ but our sample does not resolve Gru 1's velocity dispersion. The radial coordinates of Tuc 2 and Gru 1 in Galactic phase space suggest that their orbits are among the most energetic within a distance of <~300pc. Moreover, their proximity to each other in this space arises naturally if both objects are trailing the Large Magellanic Cloud.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/857/145
- Title:
- MagLiteS Carina II and Carina III spectroscopy
- Short Name:
- J/ApJ/857/145
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Magellan/IMACS, Anglo-Australian Telescope/AAOmega+2dF, and Very Large Telescope/GIRAFFE+FLAMES spectroscopy of the Carina II (CarII) and Carina III (CarIII) dwarf galaxy candidates, recently discovered in the Magellanic Satellites Survey (MagLiteS). We identify 18 member stars in Car II, including two binaries with variable radial velocities and two RR Lyrae stars. The other 14 members have a mean heliocentric velocity v_hel_=477.2+/-1.2km/s and a velocity dispersion of {sigma}_v_=3.4_-0.8_^+1.2^km/s. Assuming Car II is in dynamical equilibrium, we derive a total mass within the half-light radius of 1.0_-0.4_^+0.8^x10^6^M_{sun}_, indicating a mass-to-light ratio of 369_-161_^+309^M_{sun}_/L_{sun}_. From equivalent width measurements of the calcium triplet lines of nine red giant branch (RGB) stars, we derive a mean metallicity of [Fe/H]=-2.44+/-0.09 with dispersion {sigma}_[Fe/H]_=0.22_-0.07_^+0.10^. Considering both the kinematic and chemical properties, we conclude that CarII is a dark-matter-dominated dwarf galaxy. For CarIII, we identify four member stars, from which we calculate a systemic velocity of v_hel_=284.6_-3.1_^+3.4^km/s. The brightest RGB member of CarIII has a metallicity of [Fe/H]=-1.97+/-0.12. Due to the small size of the Car III spectroscopic sample, we cannot conclusively determine its nature. Although these two systems have the smallest known physical separation ({Delta}d~10kpc) among Local Group satellites, the large difference in their systemic velocities, ~200km/s, indicates that they are unlikely to be a bound pair. One or both systems are likely associated with the Large Magellanic Cloud (LMC), and may remain LMC satellites today. No statistically significant excess of {gamma}-ray emission is found at the locations of Car II and Car III in eight years of Fermi-LAT data.
- ID:
- ivo://CDS.VizieR/J/AJ/159/114
- Title:
- Magnetic CVs spectra & other variable objects II.
- Short Name:
- J/AJ/159/114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the second paper of a series presenting our search for magnetic cataclysmic variables (mCVs) among candidates selected mostly from the Catalina Real-Time Transient Survey. We present the identification spectra, obtained at the SOAR Telescope, as well as magnitudes and Gaia distances for 45 objects. Of these, 39 objects are identified as CVs, from which 8 targets show observational characteristics of mCVs, being 7 polars and 1 intermediate polar. The remaining 31 CVs in our sample are probably non-magnetic systems, in low (22 systems) or high (9 systems) accretion states. Six targets of the sample are not CVs (5 active galactic nuclei and 1 T-Tauri star). Among the 8 objects with mCV spectra, 6 are new classifications. Three polars were observed in low-accretion state, either revealing photospheric features of the secondary star and allowing the estimation of their spectral type, or presenting H{beta} Zeeman components associated to the white dwarf (WD) magnetic field. In addition to the results obtained in the first paper of the series, and depending on the confirmation of these classifications by observational follow-up, our results would increase the sample of known polars by about 9%.
- ID:
- ivo://CDS.VizieR/J/A+A/612/A57
- Title:
- MASCARA-2 b (HD185603) light curves and spectra
- Short Name:
- J/A+A/612/A57
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we present MASCARA-2 b, a hot Jupiter transiting the m_V_=7.6 A2 star HD 185603. Since early 2015, MASCARA has taken more than 1.6 million flux measurements of the star, corresponding to a total of almost 3000 hours of observations, revealing a periodic dimming in the flux with a depth of 1.3%. Photometric follow-up observations were performed with the NITES and IAC80 telescopes and spectroscopic measurements were obtained with the Hertzsprung SONG telescope. We find MASCARA-2 b orbits HD 185603 with a period of 3.474119^+0.000005^_-0.000006_ days at a distance of 0.057+/-0.006AU, has a radius of 1.83+/-0.07R_J_ and place a 99 % upper limit on the mass of <17M_J_. HD 185603 is a rapidly rotating early-type star with an effective temperature of 8980^+90^_-130_K and a mass and radius of 1.89^+0.06^_-0.05_M_sun_, 1.60+/-0.06R_sun_, respectively. Contrary to most other hot Jupiters transiting early-type stars, the projected planet orbital axis and stellar spin axis are found to be aligned with {lambda}=0.6+/-4{deg}. The brightness of the host star and the high equilibrium temperature, 2260+/-50K, of MASCARA-2 b make it a suitable target for atmospheric studies from the ground and space. Of particular interest is the detection of TiO, which has recently been detected in the similarly hot planets WASP-33 b and WASP-19 b.
- ID:
- ivo://CDS.VizieR/J/A+A/606/A73
- Title:
- MASCARA-1 b (HD201585) light curves and spectra
- Short Name:
- J/A+A/606/A73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of MASCARA-1 b, the first exoplanet discovered with the Multi-site All-Sky CAmeRA (MASCARA). It is a hot Jupiter orbiting a bright m_V_=8.3, rapidly rotating (vsini>100km/s) A8 star with a period of 2.148780+/-0.000008 days. The planet has a mass and radius of 3.7+/-0.9M_J_ and 1.5+/-0.3R_J_, respectively. As with most hot Jupiters transiting early-type stars we find a misalignment between the planet orbital axis and the stellar spin axis, which may be signature of the formation and migration histories of this family of planets. MASCARA-1 b has a mean density of 1.5+/-0.9g/cm^3^ and an equilibrium temperature of 2570^+50^_-30_K, one of the highest temperatures known for a hot Jupiter to date. The system is reminiscent of WASP-33, but the host star lacks apparent delta-scuti variations, making the planet an ideal target for atmospheric characterization. We expect this to be the first of a series of hot Jupiters transiting bright early-type stars that will be discovered by MASCARA.
- ID:
- ivo://CDS.VizieR/V/127A
- Title:
- MASH Catalogues of Planetary Nebulae
- Short Name:
- V/127A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Macquarie/AAO/Strasbourg H{alpha} Planetary Nebula Catalogue (MASH) contains 903 new true, likely and possible Galactic Planetary Nebulae (PNe) discovered from the AAO/UKST H{alpha} survey of the southern Galactic plane. The combination of depth, resolution, uniformity, and areal coverage of the H {alpha}survey has opened up an hitherto unexplored region of parameter space permitting the detection of this significant new PN sample. This catalogue includes also the spectra of the PNe as FITS files (in the "sp" subdirectory), and a gallery of images created as a combination of the H{alpha} and short red images of the survey. The second part, MASH-II (table mash2.dat) consists of over 300 true, likely and possible new Galactic PNe found after re-examination of the entire AAO/UKST H{alpha} survey of the Southern Galactic Plane in digital form. Over 240 of these new candidates were confirmed as bona fide PNe on the basis of spectroscopic observations. The spectra of this supplement will be available in the future.
- ID:
- ivo://CDS.VizieR/J/A+A/617/A66
- Title:
- Massive eclipsing SB2 in Arches cluster spectra
- Short Name:
- J/A+A/617/A66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out a spectroscopic variability survey of some of the most massive stars in the Arches cluster, using K-band observations obtained with SINFONI on the VLT. One target, F2, exhibits substantial changes in radial velocity; in combination with new KMOS and archival SINFONI spectra, its primary component is found to undergo radial velocity variation with a period of 10.483+/-0.002d and an amplitude of ~350km/s. A secondary radial velocity curve is also marginally detectable. We reanalyse archival NAOS-CONICA photometric survey data in combination with our radial velocity results to confirm this object as an eclipsing SB2 system, and the first binary identified in the Arches. We model it as consisting of an 82+/-12M_{sun}_ WN8-9h primary and a 60+/-8M_{sun}_ O5-6 Ia+ secondary, and as having a slightly eccentric orbit, implying an evolutionary stage prior to strong binary interaction. As one of four X-ray bright Arches sources previously proposed as colliding-wind massive binaries, it may be only the first of several binaries to be discovered in this cluster, presenting potential challenges to recent models for the Arches' age and composition. It also appears to be one of the most massive binaries detected to date; the primary's calculated initial mass of >~120M_{sun}_ would arguably make this the most massive binary known in the Galaxy.
- ID:
- ivo://CDS.VizieR/J/A+A/646/A83
- Title:
- 12 massive lensing clusters MUSE observations
- Short Name:
- J/A+A/646/A83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectroscopic surveys of massive galaxy clusters reveal the properties of faint background galaxies thanks to the magnification provided by strong gravitational lensing. We present a systematic analysis of integral-field- spectroscopy observations of 12 massive clusters, conducted with the Multi Unit Spectroscopic Explorer (MUSE). All data were taken under very good seeing conditions (~0.6") in effective exposure times between two and 15 hrs per pointing, for a total of 125 hrs. Our observations cover a total solid angle of ~23-arcmin^2^ in the direction of clusters, many of which were previously studied by the MAssive Clusters Survey (MACS), Frontier Fields (FFs), Grism Lens-Amplified Survey from Space (GLASS) and Cluster Lensing And Supernova survey with Hubble (CLASH) programmes. The achieved emission line detection limit at 5sigma for a point source varies between (0.77-1.5)x10^-18^erg/s/cm^2^ at 7000{AA}. We present our developed strategy to reduce these observational data, detect continuum sources and line emitters in the datacubes, and determine their redshifts. We constructed robust mass models for each cluster to further confirm our redshift measurements using strong-lensing constraints, and identified a total of 312 strongly lensed sources producing 939 multiple images. The final redshift catalogues contain more than 3300 robust redshifts, of which 40% are for cluster members and ~30% are for lensed Lyman-alpha emitters. Fourteen percent of all sources are line emitters that are not seen in the available HST images, even at the depth of the FFs (~29 AB). We find that the magnification distribution of the lensed sources in the high- magnification regime (mu=2-25) follows the theoretical expectation of N(z){prop.to}mu^-2^. The quality of this dataset, number of lensed sources, and number of strong-lensing constraints enables detailed studies of the physical properties of both the lensing cluster and the background galaxies. The full data products from this work, including the datacubes, catalogues, extracted spectra, ancillary images, and mass models, are made available to the community.
- ID:
- ivo://CDS.VizieR/J/ApJS/247/17
- Title:
- Massive stars in APOGEE2 Survey. III.
- Short Name:
- J/ApJS/247/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have applied the semi-empirical spectral analysis, developed by the Sloan Digital Sky Survey (SDSS)-IV/Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE2) Massive Star Team, to a large sample of new O- and B-type stars identified along the Sagittarius spiral arm, in the direction of the southern star clusters NGC3603 and NGC3576. We obtained H-band spectra for 265 point sources, using the APOGEE2-S spectrograph at the du Pont Telescope at the Las Campanas Observatory. We analyzed the associated spectral features deriving spectral types, as well as the massive star distribution along the line of sight. From a total of 265 science targets, 95 are classified as mid- to late-O-type stars (for which only 10 O-type stars are previously known in the literature), 38 are found to be early- to mid-B-type stars, and 32 are classified as either yellow or blue supergiants, completing a total of 165 massive stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/873/66
- Title:
- Massive stars in SDSS/APOGEE-2. II. W3-W4-W5
- Short Name:
- J/ApJ/873/66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work, we have applied a semi-empirical spectral classification method for OB-stars using the APOGEE spectrograph to a sample of candidates in the W3-W4-W5 (W345) complexes. These massive star-forming regions span over 200pc across the Perseus arm and have a notorious population of massive stars, from which a large fraction are members of various embedded and young open clusters. From 288 APOGEE spectra showing H-band spectral features typical of O- and B-type sources, 46 probably correspond to previously unknown O-type stars. Therefore, we confirm that Br11-Br13 together with HeII {lambda}16923 (7-12) and HeII {lambda}15723 (7-13) lines contained in the APOGEE spectral bands are useful in providing spectral classification down to one spectral sub-class for massive stars in regions as distant as d~2kpc. The large number of newly found O-type stars as well as the numerous intermediate-mass population confirm that W345 is a very efficient massive star factory, with an integral stellar population probably amounting several thousand solar masses.