Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/360/185
- Title:
- VI photometry of the Leo II galaxy
- Short Name:
- J/MNRAS/360/185
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present V and I photometry of a 9.4'x9.4' field centered on the dwarf spheroidal galaxy Leo II. The Tip of the Red Giant Branch is identified at I^TRGB^=17.83+/-0.03 and adopting <[M/H]>=-1.53+/-0.2 from the comparison of RGB stars with Galactic templates, we obtain a distance modulus (m-M)_0=21.84+/-0.13, corresponding to a distance D=233+/-15kpc. Two significant bumps have been detected in the Luminosity Function of the Red Giant Branch. The fainter bump (B1, at V=21.79+/-0.05) is the RGB bump of the dominant stellar population while the brightest one (B2, at V=21.36+/-0.05) may be identified as the Asymptotic Giant Branch Clump of the same population. The luminosity of the main RGB bump (B1) suggest that the majority of RGB stars in Leo II belongs to a population that is >~4Gyr younger than the classical Galactic globular clusters. The stars belonging to the He-burning Red Clump are shown to be significantly more centrally concentrated than RR Lyrae and Blue Horizontal Branch stars, probing the existence of an age/metallicity radial gradient in this remote dwarf spheroidal.
- ID:
- ivo://CDS.VizieR/J/ApJ/806/133
- Title:
- Virgo cluster ETGs: GC and galaxy diffuse light
- Short Name:
- J/ApJ/806/133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a kinematic analysis of the globular cluster (GC) systems and diffuse stellar light of four intermediate luminosity (sub-L*) early-type galaxies in the Virgo cluster based on Gemini Multi-Object Spectrographs (GMOS) data. Our galaxy sample is fainter (-23.8<M_K_<-22.7) than most previous studies, nearly doubling the number of galaxies in this magnitude range that now have GC kinematics. The data for the diffuse light extends to 4R_e_, and the data for the GCs reaches 8-12R_e_. We find that the kinematics in these outer regions are all different despite the fact that these four galaxies have similar photometric properties, and are uniformly classified as "fast rotators" from their stellar kinematics within 1R_e_. The GC systems exhibit a wide range of kinematic morphology. The rotation axis and amplitude can change between the inner and outer regions, including a case of counter-rotation. This difference shows the importance of wide-field kinematic studies, and shows that stellar and GC kinematics can change significantly as one moves beyond the inner regions of galaxies. Moreover, the kinematics of the GC systems can differ from that of the stars, suggesting that the formation of the two populations are also distinct.
- ID:
- ivo://CDS.VizieR/J/ApJS/111/143
- Title:
- Virgo cluster ultraviolet sources
- Short Name:
- J/ApJS/111/143
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze three UV images covering a ~100 square degree field toward the Virgo cluster, obtained by the FAUST space experiment. We detect 191 sources to a signal-to-noise ratio of 4.4 and identify 94% of them. Most sources have optical counterparts in existing catalogs, and about half are identified as galaxies. Some sources with no listed counterpart were observed at the Wise Observatory. We present the results of low-resolution visible spectrophotometry and discuss the foreground 101 stellar sources and the 76 detected galaxies, both in the cluster and in the foreground or background. We derive conclusions on star formation properties of galaxies and on the total UV flux from discrete and diffuse sources in the cluster. We test for the presence of intracluster dust, determine the clustering properties of UV emitting galaxies, and derive the UV luminosity function of Virgo galaxies.
- ID:
- ivo://CDS.VizieR/J/A+AS/118/441
- Title:
- Virgo & Fornax clusters galaxies UBVRI data
- Short Name:
- J/A+AS/118/441
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photoelectric multi-aperture photometry in UBVRI of 171 and 46 galaxies in the Virgo and Fornax clusters, respectively. Many of the galaxies have not been observed in at least one of these passbands before. We discuss the reduction and transformation into the Cousins photometric system as well as the extinction coefficients obtained between 1990 and 1993.
- ID:
- ivo://CDS.VizieR/II/286
- Title:
- VIRMOS deep imaging survey. VVDS-F02 catalog
- Short Name:
- II/286
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Franco-Italian VIRMOS project has delivered the VIMOS spectrograph for the European Southern Observatory Very Large Telescope (ESO-VLT). VIMOS is a VIsible imaging Multi-Object Spectrograph with outstanding multiplex capabilities: with 10 arcsec slits, spectra can be taken of 600 objects simultaneously. In integral field mode, a 6400-fibre Integral Field Unit (IFU) provides spectroscopy for all objects covering a 54x54arcsec^2^ area.
- ID:
- ivo://CDS.VizieR/J/MNRAS/503/2265
- Title:
- VISTA and Subaru/HSC obs. of Upper Scorpius
- Short Name:
- J/MNRAS/503/2265
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We aim at identifying very low-mass isolated planetary-mass member candidates in the nearest OB association to the Sun, Upper Scorpius (145pc; 5-10Myr), to constrain the form and shape of the luminosity function and mass spectrum in this regime. We conducted a deep multi-band (Y=21.2, J=20.5, Z=22.0mag) photometric survey of six square degrees in the central region of Upper Scorpius. We extend the current sequence of astrometric and spectroscopic members by about two magnitudes in Y and one magnitude in J, reaching potentially T-type free-floating members in the association with predicted masses below 5 Jupiter masses, well into the planetary-mass regime. We extracted a sample of 57 candidates in this area and present infrared spectroscopy confirming two of them as young L-type members with characteristic spectral features of 10Myr-old brown dwarfs. Among the 57 candidates, we highlight 10 new candidates fainter than the coolest members previously confirmed spectroscopically. We do not see any obvious sign of decrease in the mass spectrum of the association, suggesting that star processes can form substellar objects with masses down to 4-5 Jupiter masses.
1998. V360 Lac spectroscopy
- ID:
- ivo://CDS.VizieR/J/A+A/455/1037
- Title:
- V360 Lac spectroscopy
- Short Name:
- J/A+A/455/1037
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We include existing photometric and spectroscopic material with new observations in a detailed study of the Be+F binary V360 Lac. We used the programs FOTEL and KOREL to derive an improved linear ephemeris and to disentangle the line profiles of both binary components and telluric lines. The BINSYN software suite (described in the paper) is used to calculate synthetic light curves and spectra to fit the UBV photometry, an IUE spectrum, blue and red ground-based spectra, and observed radial-velocity curves.
- ID:
- ivo://CDS.VizieR/J/AJ/145/45
- Title:
- V light curve of BZ Camelopardalis
- Short Name:
- J/AJ/145/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Sequences of spectra of the nova-like cataclysmic variable (CV) BZ Cam were acquired on nine nights in 2005-2006 in order to study the time development of episodes of wind activity known to occur frequently in this star. We confirm the results of Ringwald & Naylor that the P-Cygni absorption components of the lines mostly evolve from higher expansion velocity to lower velocity as an episode progresses. We also commonly find blueshifted emission components in the H{alpha} line profile, whose velocities and durations strongly suggest that they are also due to the wind. Curiously, Ringwald & Naylor reported common occurrences of redshifted H{alpha} emission components in their BZ Cam spectra. We have attributed these emission components in H{alpha} to occasions when gas concentrations in the bipolar wind (both front side and back side) become manifested as emission lines as they move beyond the disk's outer edge. We also suggest, based on changes in the P-Cygni profiles during an episode, that the progression from larger to smaller expansion velocities is due to the higher velocity portions of a wind concentration moving beyond the edge of the continuum light of the disk first, leaving a net redward shift of the remaining absorption profile. We derive a new orbital ephemeris for BZ Cam, using the radial velocity of the core of the HeI{lambda}5876 line, finding P=0.15353(4). Using this period, the wind episodes in BZ Cam are found to be concentrated near the inferior conjunction of the emission line source. This result helps confirm that the winds in nova-like CVs are often phase dependent, in spite of the puzzling implication that such winds lack axisymmetry. We argue that the radiation-driven wind in BZ Cam receives an initial boost by acting on gas that has been lifted above the disk by the interaction of the accretion stream with the disk, thereby imposing flickering timescales onto the wind events, as well as leading to an orbital modulation of the wind due to the non-axisymmetric nature of the stream/disk interaction. Simultaneous photometry and spectroscopy were acquired on three nights in order to test the possible connection between flickering continuum light and the strength of the front-side wind. We found strong agreement on one night, some agreement on another, and no agreement on the third. We suggest that some flickering events lead to only back-side winds which will not have associated P-Cygni profiles.
2000. V light curve of RW Aur
- ID:
- ivo://CDS.VizieR/J/AJ/146/112
- Title:
- V light curve of RW Aur
- Short Name:
- J/AJ/146/112
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- RW Aur A is a classical T Tauri star, believed to have undergone a reconfiguration of its circumstellar environment as a consequence of a recent flyby of its stellar companion, RW Aur B. This interaction stripped away part of the circumstellar disk of RW Aur A, leaving a tidally disrupted "arm" and a short truncated circumstellar disk. We present photometric observations of the RW Aur system from the Kilodegree Extremely Little Telescope survey showing a long and deep dimming that occurred from 2010 September until 2011 March. The dimming has a depth of ~2mag, a duration of ~180 days, and was confirmed by archival observations from American Association of Variable Star Observers. We suggest that this event is the result of a portion of the tidally disrupted disk occulting RW Aur A, specifically a fragment of the tidally disrupted arm. The calculated transverse linear velocity of the occulter is in excellent agreement with the measured relative radial velocity of the tidally disrupted arm. Using simple kinematic and geometric arguments, we show that the occulter cannot be a feature of the RW Aur A circumstellar disk, and we consider and discount other hypotheses. We also place constraints on the thickness and semimajor axis of the portion of the arm that occulted the star.
