- ID:
- ivo://CDS.VizieR/J/ApJ/868/129
- Title:
- Lensing analysis in Abell 370
- Short Name:
- J/ApJ/868/129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new gravitational lens model of the Hubble Frontier Fields cluster Abell 370 (z=0.375) using imaging and spectroscopy from Hubble Space Telescope and ground-based spectroscopy. We combine constraints from a catalog of 909 weakly lensed galaxies and 39 multiply imaged sources comprised of 114 multiple images, including a system of multiply imaged candidates at z=7.84+/-0.02, to obtain a best-fit mass distribution using the cluster lens modeling code strong and weak lensing united. As the only analysis of A370 using strong and weak lensing constraints from Hubble Frontier Fields (HFF) data, our method provides an independent check of assumptions on the mass distribution used in other methods. Convergence, shear, and magnification maps are made publicly available through the HFF website (http://www.stsci.edu/hst/campaigns/frontier-fields). We find that the model we produce is similar to models produced by other groups, with some exceptions due to the differences in lensing code methodology. In an effort to study how our total projected mass distribution traces light, we measure the stellar mass density distribution using Spitzer/Infrared array camera imaging. Comparing our total mass density to our stellar mass density in a radius of 0.3Mpc, we find a mean projected stellar to total mass ratio of <f*>=0.011+/-0.003 (stat.) using the diet Salpeter initial mass function. This value is in general agreement with independent measurements of <f*> in clusters of similar total mass and redshift.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/723/1678
- Title:
- LensPerfect A1689 analysis
- Short Name:
- J/ApJ/723/1678
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a strong lensing (SL) mass model of A1689 which resolves substructures an estimated 25kpc across within the central ~400kpc diameter. We achieve this resolution by perfectly reproducing the observed (strongly lensed) input positions of 168 multiple images of 55 knots residing within 135 images of 42 galaxies. Our model makes no assumptions about light tracing mass, yet we reproduce the brightest visible structures with some slight deviations. A1689 remains one of the strongest known lenses on the sky, with an Einstein radius of R_E_=47.0+/-1.2" (143^+3^_-4_kpc) for a lensed source at z_s_=2. We find that a single Navarro-Frenk-White (NFW) or Sersic profile yields a good fit simultaneously (with only slight tension) to both our SL mass model and published weak lensing (WL) measurements at larger radius (out to the virial radius). Our SL model prefers slightly higher concentrations than previous SL models, bringing our SL+WL constraints in line with other recent derivations. Our results support those of previous studies which find A1689 has either an anomalously large concentration or significant extra mass along the line of sight (perhaps in part due to triaxiality).
- ID:
- ivo://CDS.VizieR/J/AJ/134/566
- Title:
- Leo II stellar kinematics
- Short Name:
- J/AJ/134/566
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the projected velocity dispersion profile for the remote (d=233kpc) Galactic dwarf spheroidal (dSph) galaxy Leo II, based on 171 discrete stellar radial velocities that were obtained from medium-resolution spectroscopy using the FLAMES/GIRAFFE spectrograph at the European Southern Observatory, Chile.
- 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.
7885. 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://nasa.heasarc/lspmnorth
- Title:
- Lepine and Shara Northern Stars Proper Motion (LSPM-North) Catalog
- Short Name:
- LSPMNORTH
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The LSPM catalog is a comprehensive list of 61,977 stars north of the J2000 celestial equator that have proper motions larger than 0.15" yr<sup>-1</sup> (local-background-stars frame). The catalog has been generated primarily as a result of the authors' systematic search for high-proper-motion stars in the Digitized Sky Surveys using their SUPERBLINK software (note that this catalog is consequently also sometimes referred to as the SUPERBLINK Catalog). At brighter magnitudes, the catalog incorporates stars and data from the Tycho-2 Catalog and also, to a lesser extent, from the All-Sky Compiled Catalogue of 2.5 million stars (ASCC-2.5: Kharchenko 2001). The LSPM catalog considerably expands over the old Luyten (Luyten Half-Second (LHS) and New Luyten Two-Tenths (NLTT) catalogs, superseding them for northern declinations. Positions are given with an accuracy of <~ 100 milliarcseconds (mas) at the 2000.0 epoch, and absolute proper motions are given with an accuracy of ~ 8 mas/yr. Corrections to the local-background-stars proper motions have been calculated, and absolute proper motions in the extragalactic frame are given. Whenever available, the authors also give optical B<sub>T</sub> and V<sub>T</sub> magnitudes (from Tycho-2, ASCC-2.5), photographic B<sub>J</sub>, R<sub>F</sub>, and I<sub>N</sub> magnitudes (from the USNO-B1 catalog), and infrared J, H, and K<sub>s</sub> magnitudes (from 2MASS). An estimated V magnitude and V-J color is also provided for nearly all catalog entries, which is useful for initial classification of the stars. The catalog is estimated to be over 99% complete at high Galactic latitudes (|b| > 15 degrees) and over 90% complete at low Galactic latitudes (|b| < 15 degrees), down to a magnitude of V = 19.0, and has a limiting magnitude V = 21.0. All the northern stars listed in the LHS and NLTT catalogs have been re-identified, and their positions, proper motions, and magnitudes reevaluated. The catalog also lists a large number of completely new objects, which promise to expand very significantly the census of red dwarfs, sub-dwarfs, and white dwarfs in the vicinity of the Sun. All of Luyten's NLTT stars north of the J2000 celestial equator that do NOT appear in the LSPM Catalog are listed in Table 3 of the published paper, together with the explanations as to why they were not included in the LSPM Catalog. This table was created by the HEASARC in June 2013 based on an electronic version of Table 1 from the reference paper which was obtained from the CDS web site (their catalog I/298). This is a service provided by NASA HEASARC .
- 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/MNRAS/435/3376
- Title:
- L_FIR_ and L_CO_ for 247 extragalactic systems
- Short Name:
- J/MNRAS/435/3376
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An analysis of 44GHz Very Large Array observations of the z=1.574 radio-loud quasar 3C 318 has revealed emission from the redshifted J=1-->0 transition of the CO molecule and spatially resolved the 6.3kpc radio jet associated with the quasar at 115GHz rest frame. The continuum-subtracted line emitter is spatially offset from the quasar nucleus by 0.33arcsec (2.82kpc in projection). This spatial offset has a significance of >8{sigma} and, together with a previously published -400km/s velocity offset measured in the J=2-->1 CO line relative to the systemic redshift of the quasar, rules out a circumnuclear starburst or molecular gas ring and suggests that the quasar host galaxy is either undergoing a major merger with a gas-rich galaxy or is otherwise a highly disrupted system. If the merger scenario is correct, then the event may be in its early stages, acting as the trigger for both the young radio jets in the quasar and a starburst in the merging galaxy. The total molecular gas mass in the spatially offset line emitter as measured from the ground-state CO line MH_2_=3.7(+/-0.4)x10^10^ ({alpha}CO/0.8)M_{sun}_. Assuming that the line emitter can be modelled as a rotating disc, an inclination-dependent upper limit is derived for its dynamical mass M_dyn_sin^2^(i)<3.2x10^9^M_{sun}_, suggesting that for MH2 to remain less than M_dyn_ the inclination angle must be i<16{deg}. The far-infrared and CO luminosities of 246 extragalactic systems are collated from the literature for comparison. The high molecular gas content of 3C 318 is consistent with that of the general population of high-redshift quasars and submillimetre galaxies.
7890. LFT Catalogue
- ID:
- ivo://CDS.VizieR/I/54A
- Title:
- LFT Catalogue
- Short Name:
- I/54A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalogue, published in 1955, provides data about stars known to have proper motions exceeding 0.5" annually. Note that a more recent version, known as the "LHS" catalogue and containing 4471 stars, was published later in 1987 (catalogue I/87)