- ID:
- ivo://CDS.VizieR/J/A+A/454/185
- Title:
- EROS-2 microlensing parameters
- Short Name:
- J/A+A/454/185
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new EROS-2 measurement of the microlensing optical depth toward the Galactic Bulge. Light curves of 5.6x10^6^ clump-giant stars distributed over 66deg^2^ of the Bulge were monitored during seven Bulge seasons. 120 events were found with apparent amplifications greater than 1.6 and Einstein radius crossing times in the range 5d<t_E_<400d. This is the largest existing sample of clump-giant events and the first to include northern Galactic fields.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/303/137
- Title:
- EROS Variables: Cepheids in the bar of LMC
- Short Name:
- J/A+A/303/137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CCD phase-binned light curves at 490nm for 97 Cepheid variable stars in the bar of the LMC. The photometry was obtained as part of the French EROS project and has excellent phase coverage, permitting accurate decomposition into Fourier components. We identify as `sinusoidal' or s-Cepheids those stars with periods less than 5.5d and small second-harmonic components. These stars comprise ~30% of our sample and most form a sequence ~1mag brighter than the LMC classical Cepheids in the period-luminosity diagram. They are also generally bluer and have lower-amplitude light curves. We infer that the s-Cepheids are first-overtone pulsators because, when their periods are converted to expected fundamental-mode values, they obey a common period-luminosity-colour relation with classical Cepheids. This also confirms the reality of the colour term in the Cepheid period-luminosity-colour relation. Further, the blue edge of the classical Cepheid instability strip agrees well with the theoretical calculations for the fundamental mode made by Chiosi et al. 1993 (=1993ApJS...86..541C) for the Hertzsprung-Russell and period-luminosity diagrams, but we find that our observed s-Cepheids are >0.2mag brighter and bluer than the Chiosi et al. predictions for the first-overtone. We identify a number of features in plots of our stars' Fourier-component amplitude ratios and phase differences. These features have been identified with resonances between different pulsation modes. In the LMC we find these features seem to occur at periods very similar to Galactic ones for classical Cepheids, but at different periods for s-Cepheids. We discover a double-mode Cepheid in the LMC, for which P(first overtone)/P(fundamental)=0.710+/-0.001, very similar to observed ratios for Galactic double-mode Cepheids.
- ID:
- ivo://CDS.VizieR/J/AJ/114/850
- Title:
- Errors in the FK5 Catalog
- Short Name:
- J/AJ/114/850
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents new positions for 689 FK5 stars determined directly in the extragalactic reference system from CCD scan observations made with the Flagstaff Astrometric Scanning Transit Telescope (FASTT). All the observations were made in 1994-1996 with an accuracy of ~+/-40mas in each coordinate. When these positions are compared with their counterparts in the FK5 catalog, systematic errors in the FK5 are found that vary in both right ascension and declination and can be as large as 100 mas in magnitude. No magnitude-dependent errors in the FK5 were found. Moreover, the true error in FK5 star positions is determined to be ~+/-80mas in both coordinates or two times the expected catalog positional errors. There is an excellent agreement between the systematic errors in the FK5 found in this paper and those presented in Lindegren et al. (1995A&A...304...44L) comparing FK5 and Hipparcos 30-month star positions. By comparing corresponding FASTT and FK5 star positions, the link between the optical and extragalactic reference frames was determined and is given by the following rotations ({omega}_x_,{omega}_y_,{omega}_z_) = (3+/-5, 25+/-5, 16+/-4) (s.e.) mas, which agree well with previous determinations made by other investigators. Two of the rotations ({omega}_y_,{omega}_z_) are significantly larger than their standard errors and, therefore, presumably real. Finally, since these rotations are small (<=25mas), the FK5 and extragalactic reference frames must be closely aligned to one another.
- ID:
- ivo://CDS.VizieR/J/MNRAS/465/3039
- Title:
- Eruptive variable protostars from VVV EW
- Short Name:
- J/MNRAS/465/3039
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In a companion work (Contreras Pena et al., 2017MNRAS.465.3011C, Paper I), we detected a large population of highly variable Young Stellar Objects (YSOs) in the Vista Variables in the Via Lactea (VVV) survey, typically with class I or flat spectrum spectral energy distributions and diverse light-curve types. Here we present infrared spectra (0.9-2.5 {mu}m) of 37 of these variables, many of them observed in a bright state. The spectra confirm that 15/18 sources with eruptive light curves have signatures of a high accretion rate, either showing EXor-like emission features ({Delta}v=2 CO, Br{gamma}) and/or FUor-like features ({Delta}v=2 CO and H_2_O strongly in absorption). Similar features were seen in some long-term periodic YSOs and faders but not in dippers or short-term variables. The sample includes some dusty Mira variables (typically distinguished by smooth Mira-like light curves), two cataclysmic variables and a carbon star. In total, we have added 19 new objects to the broad class of eruptive variable YSOs with episodic accretion. Eruptive variable YSOs in our sample that were observed at bright states show higher accretion luminosities than the rest of the sample. Most of the eruptive variables differ from the established FUor and EXor subclasses, showing intermediate outburst durations and a mixture of their spectroscopic characteristics. This is in line with a small number of other recent discoveries. Since these previously atypical objects are now the majority amongst embedded members of the class, we propose a new classification for them as MNors. This term (pronounced emnor) follows V1647 Ori, the illuminating star of McNeil's Nebula.
- ID:
- ivo://CDS.VizieR/J/A+A/451/881
- Title:
- ESIS BVR catalog, ELAIS-S1
- Short Name:
- J/A+A/451/881
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ESO-Spitzer extragalactic Imaging Survey (ESIS) is the optical follow up of the Spitzer Wide-Area InfraRed Extragalactic (SWIRE) survey in the ELAIS-S1 area. The multiwavelength study of galaxy emission is the key to understand the interplay of the various components of galaxies and to trace their role in cosmic evolution. ESIS provides optical identification and colors of Spitzer IR galaxies and builds the bases for photometric redshift estimates. This paper presents B, V, R Wide Field Imager observations of the first 1.5 square degree of the ESIS survey. Data reduction includes astrometric calibration, illumination and color corrections. Synthetic sources are simulated in scientific and super-sky-flat images, with the purpose of estimating completeness and photometric accuracy for the survey. Number counts and color distributions are compared to literature observational and theoretical data, including non-evolutionary, PLE, evolutionary and semi-analytic Lambda-CDM galaxy models, as well as Milky Way stellar predictions. Object coordinates are defined with an accuracy as good as ~0.15" rms with respect to GSC 2.2; flux uncertainties are ~2, 10, 20% at mag. 20, 23, 24 respectively (Vega); we reach 95% completeness at B, V~25 and R~24.5. ESIS galaxy number counts are in good agreement with previous works and are best reproduced by evolutionary and hierarchical Lambda-CDM scenarios.
- ID:
- ivo://CDS.VizieR/J/A+A/488/533
- Title:
- ESIS VIMOS I,z photometry of ELAIS-S1
- Short Name:
- J/A+A/488/533
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ESO-Spitzer Imaging extragalactic Survey (ESIS) is the optical follow up of the Spitzer Wide-area Infra-Red Extragalactic survey (SWIRE) in the ELAIS-S1 region of the sky. We present VIMOS I and z band imaging belonging to the ESIS survey. A total of ~4 square degrees were targeted in I and ~1 in z. Accurate data processing includes removal of fringing, and mosaicking of the complex observing pattern. Completeness levels and photometric uncertainties are estimated through simulations. More than 300000 galaxies have been detected in the I band and ~50000 in the z band. Object coordinates are defined within an uncertainty of ~0.2" r.m.s., with respect to GSC 2.2. We reach a 90% average completeness at 23.1 and 22.5mag (Vega) in the I and z bands, respectively.
- ID:
- ivo://CDS.VizieR/J/A+A/444/365
- Title:
- ESO Distant Cluster Survey, EDisCS
- Short Name:
- J/A+A/444/365
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the ESO Distant Cluster Survey (EDisCS) a survey of 20 distant galaxy clusters with redshifts ranging from 0.4 to 0.8. Candidate clusters were chosen from among the brightest objects identified in the Las Campanas Distant Cluster Survey (LCDCS), half with estimated redshift z_est_~0.5 and half with z_est_~0.8. They were confirmed by identifying red sequences in moderately deep two colour data from VLT/FORS2. For confirmed candidates we have assembled deep three-band optical photometry using VLT/FORS2, deep near-infrared photometry in one or two bands using NTT/SOFI, deep optical spectroscopy using VLT/FORS2, wide field imaging in two or three bands using the ESO Wide Field Imager, and HST/ACS mosaic images for 10 of the most distant clusters. This first paper presents our sample and the VLT photometry we have obtained. We present images, colour magnitude diagrams and richness estimates for our clusters, as well as giving redshifts and positions for the brightest cluster members. Subsequent papers will present our infrared photometry, spectroscopy, HST and wide-field imaging, as well as a wealth of further analysis and science results. Our reduced data become publicly available as these papers are accepted.
- ID:
- ivo://CDS.VizieR/J/A+A/482/419
- Title:
- ESO Distant Cluster Survey, EDisCS. II
- Short Name:
- J/A+A/482/419
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectroscopic observations of galaxies in 15 survey fields as part of the ESO Distant Cluster Survey (EDisCS). We determine the redshifts and velocity dispersions of the galaxy clusters located in these fields, and we test for possible substructure in the clusters. We obtained multi-object mask spectroscopy using the FORS2 instrument at the VLT. We reduced the data with particular attention to the sky subtraction. We implemented the method of Kelson for performing sky subtraction prior to any rebinning/interpolation of the data. From the measured galaxy redshifts, we determine cluster velocity dispersions using the biweight estimator and test for possible substructure in the clusters using the Dressler-Shectman test. The method of subtracting the sky prior to any rebinning/interpolation of the data delivers photon-noise-limited results, whereas the traditional method of subtracting the sky after the data have been rebinned/interpolated results in substantially larger noise for spectra from tilted slits. Redshifts for individual galaxies are presented and redshifts and velocity dispersions are presented for 21 galaxy clusters. For the 9 clusters with at least 20 spectroscopically confirmed members, we present the statistical significance of the presence of substructure obtained from the Dressler-Shectman test, and substructure is detected in two of the clusters. Together with data from our previous paper, spectroscopy and spectroscopic velocity dispersions are now available for 26 EDisCS clusters with redshifts in the range 0.40-0.96 and velocity dispersions in the range 166-1080km/s.
- ID:
- ivo://CDS.VizieR/J/A+A/605/A54
- Title:
- ESO 435-02/ESO 435-016 ATCA HI images
- Short Name:
- J/A+A/605/A54
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A fly-by interaction has been suggested to be one of the major explanations for enhanced star formation in blue compact dwarf (BCD) galaxies, yet no direct evidence for this scenario has been found to date. In the HI Parkes all-sky survey (HIPASS), ESO 435-IG 020 and ESO 435-G 016, a BCD pair were found in a common, extended gas envelope of atomic hydrogen, providing an ideal case to test the hypothesis that the starburst in BCDs can be indeed triggered by a fly-by interaction. Using high-resolution data from the Australia Telescope Compact Array (ATCA), we investigated HI properties and the spectral energy distribution (SED) of the BCD pair to study their interaction and star formation histories. The high-resolution HI data of both BCDs reveal a number of peculiarities, which are suggestive of tidal perturbation. Meanwhile, 40% of the HIPASS flux is not accounted for in the ATCA observations with no HI gas bridge found between the two BCDs. Intriguingly, in the residual of the HIPASS and the ATCA data, ~10% of the missing flux appears to be located between the two BCDs. While the SED-based age of the most dominant young stellar population is old enough to have originated from the interaction with any neighbors (including the other of the two BCDs), the most recent star formation activity traced by strong H{alpha} emission in ESO 435-IG 020 and the shear motion of gas in ESO 435-G 016, suggest a more recent or current tidal interaction. Based on these and the residual emission between the HIPASS and the ATCA data, we propose an interaction between the two BCDs as the origin of their recently enhanced star formation activity. The shear motion on the gas disk, potentially with re-accretion of the stripped gas, could be responsible for the active star formation in this BCD pair.
4280. ESO 362-G18 datacube
- ID:
- ivo://CDS.VizieR/J/A+A/614/A94
- Title:
- ESO 362-G18 datacube
- Short Name:
- J/A+A/614/A94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present two-dimensional stellar and gaseous kinematics of the inner 0.7x1.2kpc^2^ of the Seyfert 1.5 galaxy ESO 362-G18, derived from optical (4092-7338{AA}) spectra obtained with the GMOS integral field spectrograph on the Gemini South telescope at a spatial resolution of 170 pc and spectral resolution of 36km/s. ESO 362-G18 is a strongly perturbed galaxy of morphological type Sa or S0/a, with a minor merger approaching along the NE direction. Previous studies have shown that the [OIII] emission shows a fan-shaped extension of ~10" to the SE. We detect the [OIII] doublet, [NII] and H{alpha} emission lines throughout our FOV. The stellar kinematics is dominated by circular motions in the galaxy plane, with a kinematic position angle of ~137{deg} and is centred approximately on the continuum peak. The gas kinematics is also dominated by rotation, with kinematic position angles ranging from 122{deg} to 139{deg}, projected velocity amplitudes of the order of 100km/s, and a mean velocity dispersion of 100km/s. A double-Gaussian fit to the [OIII]{lambda}5007 and H{alpha} lines, which have the highest signal to noise ratios of the emission lines, reveal two kinematic components: (1) a component at lower radial velocities which we interpret as gas rotating in the galactic disk; and (2) a component with line of sight (LOS) velocities 100-250km/s higher than the systemic velocity, interpreted as originating in the outflowing gas within the AGN ionization cone. We estimate a mass outflow rate of 7.4x10^-2^M_{sun}_/yr in the SE ionization cone (this rate doubles if we assume a biconical configuration), and a mass accretion rate on the supermassive black hole (SMBH) of 2.2x10^-2^M_{sun}_/yr. The total ionized gas mass within 84pc of the nucleus is 3.3x10^5^M_{sun}_; infall velocities of ~34km/s in this gas would be required to feed both the outflow and SMBH accretion.