- ID:
- ivo://CDS.VizieR/J/ApJ/718/530
- Title:
- Leo IV g- and r-band photometry
- Short Name:
- J/ApJ/718/530
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present MMT/Megacam imaging of the Leo IV dwarf galaxy in order to investigate its structure and star formation history, and to search for signs of association with the recently discovered Leo V satellite. Based on parameterized fits, we find that Leo IV is round, with {epsilon}<0.23 (at the 68% confidence limit) and a half-light radius of r_h_~130pc. Additionally, we perform a thorough search for extended structures in the plane of the sky and along the line of sight. We derive our surface brightness detection limit by implanting fake structures into our catalog with stellar populations identical to that of Leo IV. We show that we are sensitive to stream-like structures with surface brightness {mu}_r_<~29.6mag/arcsec^2^, and at this limit we find no stellar bridge between Leo IV (out to a radius of ~0.5kpc) and the recently discovered, nearby satellite Leo V. Using the color-magnitude fitting package StarFISH, we determine that Leo IV is consistent with a single age (~14Gyr), single metallicity ([Fe/H]~-2.3) stellar population, although we cannot rule out a significant spread in these values. We derive a luminosity of M_V_=-5.5+/-0.3. Studying both the spatial distribution and frequency of Leo IV's "blue plume" stars reveals evidence for a young (~2Gyr) stellar population which makes up ~2% of its stellar mass.
Number of results to display per page
Search Results
3452. Leo I VI photometry
- ID:
- ivo://CDS.VizieR/J/MNRAS/354/708
- Title:
- Leo I VI photometry
- Short Name:
- J/MNRAS/354/708
- 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 I. The I magnitude of the tip of the Red Giant Branch is robustly estimated from two different datasets I^TRGB^=17.97 (^+0.05^_-0.03_). From this estimate, adopting [M/H]~-1.2 from the comparison of RGB stars with Galactic templates, we obtain a distance modulus (m-M)_0=22.02+/-0.13, corresponding to a distance D=254^+16^_-19_kpc.
- ID:
- ivo://CDS.VizieR/J/ApJ/812/158
- Title:
- Leo P RR Lyrae candidates & cumulative SFH
- Short Name:
- J/ApJ/812/158
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Leo P is a low-luminosity dwarf galaxy discovered through the blind HI Arecibo Legacy Fast ALFA survey. The HI and follow-up optical observations have shown that Leo P is a gas-rich dwarf galaxy with active star formation, an underlying older population, and an extremely low oxygen abundance. We have obtained optical imaging with the Hubble Space Telescope to two magnitudes below the red clump in order to study the evolution of Leo P. We refine the distance measurement to Leo P to be 1.62+/-0.15Mpc, based on the luminosity of the horizontal branch stars and 10 newly identified RR Lyrae candidates. This places the galaxy at the edge of the Local Group, ~0.4Mpc from Sextans B, the nearest galaxy in the NGC 3109 association of dwarf galaxies of which Leo P is clearly a member. The star responsible for ionizing the HII region is most likely an O7V or O8V spectral type, with a stellar mass >~25M_{sun}_. The presence of this star provides observational evidence that massive stars at the upper end of the initial mass function are capable of being formed at star formation rates as low as ~10^-5^M_{sun}_/yr. The best-fitting star formation history (SFH) derived from the resolved stellar populations of Leo P using the latest PARSEC models shows a relatively constant star formation rate over the lifetime of the galaxy. The modeled luminosity characteristics of Leo P at early times are consistent with low-luminosity dSph Milky Way satellites, suggesting that Leo P is what a low-mass dSph would look like if it evolved in isolation and retained its gas. Despite the very low mass of Leo P, the imprint of reionization on its SFHIs subtle at best, and consistent with being totally negligible. The isolation of Leo P, and the total quenching of star formation of Milky Way satellites of similar mass, implies that the local environment dominates the quenching of the Milky Way satellites.
- ID:
- ivo://CDS.VizieR/J/MNRAS/415/1479
- Title:
- LESS photometric redshift survey
- Short Name:
- J/MNRAS/415/1479
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derive photometric redshifts from 17-band optical to mid-infrared photometry of 78 robust radio, 24um and Spitzer IRAC counterparts to 72 of the 126 submillimetre galaxies (SMGs) selected at 870um by LABOCA observations in the Extended Chandra Deep Field-South (ECDF-S). We test the photometric redshifts of the SMGs against the extensive archival spectroscopy in the ECDF-S.
- ID:
- ivo://CDS.VizieR/J/PASP/117/676
- Title:
- LHS faint proper-motion stars
- Short Name:
- J/PASP/117/676
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present low-resolution spectroscopic observations of faint proper-motion stars from the LHS Catalogue, concentrating on stars with m_r_>16.5 and {mu}>0.5"/yr. The present paper includes observations and spectral classifications for 294 M dwarfs, M subdwarfs (sdM), and extreme M subdwarfs (esdM). We also identify white dwarfs among the faintest LHS stars. We have cross-referenced this sample against the Two Micron All Sky Survey (2MASS) sources, and list data for the detected objects. We discuss stars of individual interest, as well as the characteristics of the overall sample. As expected, a significant number of the stars in this proper-motion-selected sample are halo subdwarfs, including an esdM dwarf, LHS 3481, that is likely to lie within 20pc of the Sun. None of the subdwarfs show H{alpha} emission.
- ID:
- ivo://CDS.VizieR/J/A+A/545/A85
- Title:
- LHS1070 photometry and spectroscopy
- Short Name:
- J/A+A/545/A85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- LHS 1070 is a nearby multiple system of low mass stars. It is an important source of information for probing the low mass end of the main sequence, down to the hydrogen-burning limit. The primary of the system is a mid-M dwarf and two components are late-M to early L dwarfs, at the star-brown dwarf transition. Hence LHS 1070 is a valuable object to understand the onset of dust formation in cool stellar atmospheres. This work aims at determining the fundamental stellar parameters of LHS 1070 and to test recent model atmospheres: BT-Dusty, BT-Settl, DRIFT, and MARCS models.
3457. LH 47 UVBRI photometry
- ID:
- ivo://CDS.VizieR/J/A+AS/123/455
- Title:
- LH 47 UVBRI photometry
- Short Name:
- J/A+AS/123/455
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table 3 lists the final photometric data of our observations. The UBVRI observations were done with the 1.54m Danish telescope at ESO on October 3rd and 4th, 1992. The CCD was ESO#28, a TEK 1024x1024 with a pixel size of 24mue corresponding to 0.377" per pixel. The total field of view is 6.4'x6.4'. A standard reduction was done with MIDAS and IRAF, the photometry was performed with DAOPHOT within IRAF. The images of Oct 4th have been calibrated using the calibration field around PG 0231+051 (Landolt 1992, Cat. <II/183>). The images of Oct 3rd have then been adopted to the system of Oct 4th. The final Table 3 lists 4613 stars with V and B-V information. In addition U-B is available for 1159 of these stars, V-R for 3519 and V-I for 2854 stars. Table 4 gives those stars from our field of view which are present in the MACS (Magellanic Catalogue of Stars; Tucholke et al. 1996, Cat. <I/221>). The table contains the MACS Id., our x and y position and our UBV photometry, and right ascension and declination from the MACS. These stars may serve to calculate an exact position for every star from Table 3 or to define a coordinate grid for comparison with other observations, such as radio or X-ray data.
- ID:
- ivo://CDS.VizieR/J/ApJ/871/108
- Title:
- Lick AGN monitoring project 2011: V band
- Short Name:
- J/ApJ/871/108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In Spring 2011, the Lick AGN Monitoring Project observed a sample of 15 bright, nearby Seyfert 1 galaxies in the V band as part of a reverberation mapping campaign. The observations were taken at six ground-based telescopes, including the West Mountain Observatory 0.91m telescope, the 0.76m Katzman Automatic Imaging Telescope, 0.6m Super-LOTIS (Livermore Optical Transient Imaging System) at Kitt Peak, the Palomar 60inch telescope, and the 2m Faulkes telescopes North and South. The V-band light curves measure the continuum variability of our sample of Seyferts on an almost daily cadence for 2-3 months. We use image-subtraction software to isolate the variability of the Seyfert nucleus from the constant V-band flux of the host galaxy for the most promising targets, and we adopt standard aperture photometry techniques for the targets with smaller levels of variability. These V-band light curves will be used, with measurements of the broad emission line flux, to measure supermassive black hole masses and to constrain the geometry and dynamics of the broad-line region through dynamical modeling techniques.
- ID:
- ivo://CDS.VizieR/J/AJ/127/1513
- Title:
- Lick indices on M67 members
- Short Name:
- J/AJ/127/1513
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We construct an integrated spectrum of the intermediate-age, solar-metallicity Galactic cluster M67, from individual spectroscopic observations of bona fide cluster members. The spectrum so obtained is used as a template to test our stellar population synthesis models, in an age and metallicity regime where such models remain largely untested. As a result, we demonstrate that our models predict a spectroscopic age of 3.5+/-0.5Gyr for M67, which is the same age we obtain from fitting isochrones to the color-magnitude diagram of the cluster. Full consistency is reached when using either H{beta}, H{gamma}, or H{delta} as the age indicator. We also check if the models, when applied to the cluster integrated spectrum, predict elemental abundances in agreement with the known detailed abundance pattern of the cluster. The models also pass the latter test, by predicting the abundances of iron, magnesium, carbon, and nitrogen in agreement with detailed abundance analyses of cluster stars to within 0.1dex. Encouraged by the high degree of consistency of our models, we apply them to the study of the integrated spectrum of the central 3" of the compact elliptical galaxy M32.
- ID:
- ivo://CDS.VizieR/J/A+A/415/123
- Title:
- Lick line-index and photometry of globular clusters
- Short Name:
- J/A+A/415/123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog contains Lick line-index and photometric measurements of extragalactic globular clusters in seven early-type galaxies (NGC 1380, 2434, 3115, 3379, 3585, 5846, and 7192) with different morphological types (E/S0) located in field and group/cluster environments. High-quality spectra were taken with the FORS2 instrument at ESO's Very Large Telescope. ~50% of our data allows an age resolution {Delta}t/t~0.3 and a metallicity resolution ~0.25-0.4dex, depending on the absolute metallicity. Globular cluster candidates are selected from deep B, V, R, I, K FORS2/ISAAC photometry with 80-100% success rate inside one effective radius. Using combined optical/near-infrared colour-colour diagrams we present a method to efficiently reduce fore-/background contamination down to <~10%.
