- ID:
- ivo://CDS.VizieR/J/ApJS/248/31
- Title:
- HST & Chandra obs. of elliptical galaxies
- Short Name:
- J/ApJS/248/31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate X-ray binary (XRB) luminosity function (XLF) scaling relations for Chandra-detected populations of low-mass XRBs (LMXBs) within the footprints of 24 early-type galaxies. Our sample includes Chandra and Hubble Space Telescope observed galaxies at D<~25Mpc that have estimates of the globular cluster (GC) specific frequency (S_N_) reported in the literature. As such, we are able to directly classify X-ray-detected sources as being coincident with unrelated background/foreground objects, GCs, or sources that are within the fields of the galaxy targets. We model the GC and field LMXB population XLFs for all galaxies separately and then construct global models characterizing how the LMXB XLFs vary with galaxy stellar mass and S_N_. We find that our field LMXB XLF models require a component that scales with S_N_ and has a shape consistent with that found for the GC LMXB XLF. We take this to indicate that GCs are "seeding" the galactic field LMXB population, through the ejection of GC LMXBs and/or the diffusion of the GCs in the galactic fields themselves. However, we also find that an important LMXB XLF component is required for all galaxies that scales with stellar mass, implying that a substantial population of LMXBs are formed "in situ," which dominates the LMXB population emission for galaxies with S_N_<~2. For the first time, we provide a framework quantifying how directly associated GC LMXBs, GC-seeded LMXBs, and in situ LMXBs contribute to LMXB XLFs in the broader early-type galaxy population.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/623/A82
- Title:
- HST/COS and FUSE UV spectra of Mrk 509
- Short Name:
- J/A+A/623/A82
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To elucidate the location, physical conditions, mass outflow rate, and kinetic luminosity of the outflow from the active nucleus of the Seyfert 1 galaxy Mrk 509 we used coordinated ultraviolet and X-ray spectral observations in 2012 to followup our lengthier campaign conducted in 2009. We observed Mrk 509 with the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST) on 2012-09-03 and 2012-10-11 coordinated with X-ray observations using the High Energy Transmission Grating on the Chandra X-ray Observatory. Our far-ultraviolet spectra used grating G140L on COS to cover wavelengths from 920-2000{AA} at a resolving power of 2000, and gratings G130M and G160M to cover 1160-1750{AA} at a resolving power of 15000. We detect variability in the blue-shifted UV absorption lines on timescales spanning 3-12 years. The inferred densities in the absorbing gas are greater than logn[cm^-3^]~3. For ionization parameters ranging over logU=-1.5 to -0.2, we constrain the distances of the absorbers to be closer than 220pc to the active nucleus. The impact on the host galaxy appears to be confined to the nuclear region.
- ID:
- ivo://CDS.VizieR/J/ApJ/804/79
- Title:
- HST/COS observations of QSOs within 600kpc of M31
- Short Name:
- J/ApJ/804/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We demonstrate the presence of an extended and massive circumgalactic medium (CGM) around Messier 31 using archival HST Cosmic Origins Spectrograph ultraviolet spectroscopy of 18 QSOs projected within two virial radii of M31 (R_vir_=300kpc). We detect absorption from SiIII at -300<~V_LSR_<~-150km/s toward all three sightlines at R<~0.2R_vir_, 3 of 4 sightlines at 0.8<~R/R_vir_<~1.1, and possibly 1 of 11 at 1.1<R/R_vir_<~1.8. We present several arguments that the gas at these velocities observed in these directions originates from the M31 CGM rather than the Local Group or Milky Way CGM or Magellanic Stream. We show that the dwarf galaxies located in the CGM of M31 have very similar velocities over similar projected distances from M31. We find a non-trivial relationship only at these velocities between the column densities (N) of all the ions and R, whereby N decreases with increasing R. At R<0.8R_vir_, the covering fraction is close to unity for Si III and C IV (f_c_~60%-97% at the 90% confidence level), but drops to f_c_<~10%-20% at R>~R_vir_. We show that the M31 CGM gas is bound, multiphase, predominantly ionized, and is more highly ionized gas at larger R. We estimate using Si II, Si III, and Si IV, a CGM metal mass of >~2x10^6^M_{sun}_ and gas mass of >~3x10^9^(Z_{sun}_/Z)M_{sun}_ within 0.2R_vir_, and possibly a factor of ~10 larger within R_vir_, implying substantial metal and gas masses in the CGM of M31.
- ID:
- ivo://CDS.VizieR/J/ApJS/230/6
- Title:
- HST -COS & -STIS absorption-line spectroscopy. II.
- Short Name:
- J/ApJS/230/6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present basic data and modeling for a survey of the cool, photoionized circumgalactic medium (CGM) of low-redshift galaxies using far-UV QSO absorption-line probes. This survey consists of "targeted" and "serendipitous" CGM subsamples, originally described in Stocke+ (Paper I, 2013ApJ...763..148S). The targeted subsample probes low-luminosity, late-type galaxies at z<0.02 with small impact parameters (<{rho}>=71kpc), and the serendipitous subsample probes higher luminosity galaxies at z<~0.2 with larger impact parameters (<{rho}>=222kpc). Hubble Space Telescope and FUSE UV spectroscopy of the absorbers and basic data for the associated galaxies, derived from ground-based imaging and spectroscopy, are presented. We find broad agreement with the COS-Halos results, but our sample shows no evidence for changing ionization parameter or hydrogen density with distance from the CGM host galaxy, probably because the COS-Halos survey probes the CGM at smaller impact parameters. We find at least two passive galaxies with HI and metal-line absorption, confirming the intriguing COS-Halos result that galaxies sometimes have cool gas halos despite no on-going star formation. Using a new methodology for fitting HI absorption complexes, we confirm the CGM cool gas mass of Paper I, but this value is significantly smaller than that found by the COS-Halos survey. We trace much of this difference to the specific values of the low-z metagalactic ionization rate assumed. After accounting for this difference, a best-value for the CGM cool gas mass is found by combining the results of both surveys to obtain log(M/M_{sun}_)=10.5+/-0.3, or ~30% of the total baryon reservoir of an L>=L^*^, star-forming galaxy.
- ID:
- ivo://CDS.VizieR/J/ApJS/240/15
- Title:
- HST/COS UV obs. of low-z SDSS galaxy groups
- Short Name:
- J/ApJS/240/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A small survey of the UV-absorbing gas in 12 low-z galaxy groups has been conducted using the Cosmic Origins Spectrograph on board the Hubble Space Telescope. Targets were selected from a large, homogeneously selected sample of groups found in the Sloan Digital Sky Survey. A critical selection criterion excluded sight lines that pass close (<1.5 virial radii) to a group galaxy, to ensure absorber association with the group as a whole. Deeper galaxy redshift observations are used both to search for closer galaxies and also to characterize these 10^13.5^-10^14.5^M_{sun}_ groups, the most massive of which are highly virialized with numerous early-type galaxies (ETGs). This sample also includes two spiral-rich groups, not yet fully virialized. At group-centric impact parameters of 0.3-2Mpc, these signal-to-noise ratios = 15-30 spectra detected HI absorption in 7 of 12 groups; high (OVI) and low (SiIII) ion metal lines are present in two-thirds of the absorption components. None of the three most highly virialized, ETG-dominated groups are detected in absorption. Covering fractions >~50% are seen at all impact parameters probed, but do not require large filling factors despite an enormous extent. Unlike halo clouds in individual galaxies, group absorbers have radial velocities that are too low to escape the group potential well without doubt. This suggests that these groups are "closed boxes" for galactic evolution in the current epoch. Evidence is presented that the cool and warm group absorbers are not a pervasive intra-group medium (IGrM), requiring a hotter (T~10^6^-10^7^K) IGrM to be present to close the baryon accounting.
- ID:
- ivo://CDS.VizieR/J/ApJ/794/75
- Title:
- HST-COS UV spectra observations of AGNs
- Short Name:
- J/ApJ/794/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ionizing fluxes from quasars and other active galactic nuclei (AGNs) are critical for interpreting their emission-line spectra and for photoionizing and heating the intergalactic medium. Using far-ultraviolet (FUV) spectra from the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST), we directly measure the rest-frame ionizing continua and emission lines for 159 AGNs at redshifts 0.001<z_AGN_<1.476 and construct a composite spectrum from 475 to 1875 {AA}. We identify the underlying AGN continuum and strong extreme ultraviolet (EUV) emission lines from ions of oxygen, neon, and nitrogen after masking out absorption lines from the H I Ly{alpha} forest, 7 Lyman-limit systems (N_HI_>=10^17.2^/cm2) and 214 partial Lyman-limit systems (14.5<logN_HI_<17.2). The 159 AGNs exhibit a wide range of FUV/EUV spectral shapes, F_v_{propto}{nu}^{alpha}_{nu}_^, typically with -2<={alpha}_{nu}_<=0 and no discernible continuum edges at 912 {AA} (H I) or 504 {AA} (He I). The composite rest-frame continuum shows a gradual break at {lambda}_br_{approx} 1000 {AA}, with mean spectral index {alpha}_{nu}_=-0.83+/-0.09 in the FUV (1200-2000 {AA}) steepening to {alpha}_{nu}_=-1.41+/-0.15 in the EUV (500-1000 {AA}). We discuss the implications of the UV flux turnovers and lack of continuum edges for the structure of accretion disks, AGN mass inflow rates, and luminosities relative to Eddington values.
- ID:
- ivo://CDS.VizieR/J/MNRAS/459/1626
- Title:
- HST Frontier Fields Herschel sources
- Short Name:
- J/MNRAS/459/1626
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a complete census of all Herschel-detected sources within the six massive lensing clusters of the HST Frontier Fields (HFF). We provide a robust legacy catalogue of 263 sources with Herschel fluxes, primarily based on imaging from the Herschel Lensing Survey and PEP/HerMES Key Programmes. We optimally combine Herschel, Spitzer and WISE infrared (IR) photometry with data from HST, VLA and ground-based observatories, identifying counterparts to gain source redshifts. For each Herschel-detected source we also present magnification factor ({mu}), intrinsic IR luminosity and characteristic dust temperature, providing a comprehensive view of dust-obscured star formation within the HFF. We demonstrate the utility of our catalogues through an exploratory overview of the magnified population, including more than 20 background sub-LIRGs unreachable by Herschel without the assistance gravitational lensing.
- ID:
- ivo://CDS.VizieR/J/MNRAS/442/1049
- Title:
- HST gz magnitude of NGC 1023 star clusters
- Short Name:
- J/MNRAS/442/1049
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Faint fuzzies (FFs) are a relatively new class of star cluster, first found in the nearby S0 galaxy NGC 1023 by Larsen & Brodie (2000AJ....120.2938L) using Wide Field Planetary Camera 2 (WFPC2) images from the Hubble Space Telescope (HST). Here, we investigate the star cluster system of NGC 1023 using an eight pointing mosaic of Advanced Camera for Surveys (ACS) images from HST. We identify blue and red normal globular clusters (two of which are particularly luminous and dense) and two ultracompact dwarf objects (with effective radius ~10pc). With our more complete spatial coverage, we also find 81 red and 27 blue FFs. We confirm the association of the red FFs with the disc of NGC 1023, consistent with them being long-lived open clusters. Half of the blue FFs appear to be associated with the dwarf satellite galaxy NGC 1023A (which was largely absent from the original HST/WFPC2 coverage), while the remainder are spatially coincident with the densest HI gas that surrounds NGC 1023. The blue FFs have colours that are consistent with young (few 100Myr old) star clusters that formed during the most recent interaction between NGC 1023 and its satellite NGC 1023A.
- ID:
- ivo://CDS.VizieR/J/ApJ/595/685
- Title:
- HST imaging in Chandra Deep Field-South
- Short Name:
- J/ApJ/595/685
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present quantitative morphological analyses of 37 Hubble Space Telescope (HST)/WFPC2 counterparts of X-ray sources in the 1Ms Chandra Deep Field South (CDFS, Cat. <J/ApJS/139/369>). We investigate (1) one-dimensional surface brightness profiles via isophotal ellipse fitting; (2) two-dimensional, point-spread function convolved, bulge+disk+nucleus profile fitting; (3) asymmetry and concentration indices compared with all ~3000 sources in our three WFPC2 fields; and (4) near-neighbor analyses comparing local environments of X-ray sources versus the field control sample. Significant nuclear point-source optical components appear in roughly half of the resolved HST/WFPC2 counterparts, showing a narrow range of FX/Fopt, nuc consistent with the several HST-unresolved X-ray sources (putative type 1 active galactic nuclei [AGNs]) in our fields.
- ID:
- ivo://CDS.VizieR/J/AJ/125/478
- Title:
- HST imaging of brightest cluster galaxies
- Short Name:
- J/AJ/125/478
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used the Hubble Space Telescope Wide Field Planetary Camera 2 to obtain Iband images of the centers of 81 brightest cluster galaxies (BCGs), drawn from a volume-limited sample of nearby BCGs. The images show a rich variety of morphological features, including multiple or double nuclei, dust, stellar disks, point-source nuclei, and central surface brightness depressions. Highresolution surface brightness profiles could be inferred for 60 galaxies. Of those, 88% have well-resolved cores.
