- ID:
- ivo://CDS.VizieR/J/ApJ/815/33
- Title:
- A Hubble diagram for quasars
- Short Name:
- J/ApJ/815/33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new method to test the {Lambda}CDM cosmological model and to estimate cosmological parameters based on the nonlinear relation between the ultraviolet and X-ray luminosities of quasars. We built a data set of 1138 quasars by merging several samples from the literature with X-ray measurements at 2keV and SDSS photometry, which was used to estimate the extinction-corrected 2500{AA} flux. We obtained three main results: (1) we checked the nonlinear relation between X-ray and UV luminosities in small redshift bins up to z~6, confirming that the relation holds at all redshifts with the same slope; (2) we built a Hubble diagram for quasars up to z~6, which is well matched to that of supernovae in the common z=0-1.4 redshift interval and extends the test of the cosmological model up to z~6; and (3) we showed that this nonlinear relation is a powerful tool for estimating cosmological parameters. Using the present data and assuming a {Lambda}CDM model, we obtain {Omega}_M_=0.22_-0.08_^+0.10^ and {Omega}_{Lambda}_=0.92-0.30_^+0.18^ ({Omega}=0.28+/-0.04 and {Omega}_{Lambda}_=0.73+/-0.08 from a joint quasar-SNe fit). Much more precise measurements will be achieved with future surveys. A few thousand SDSS quasars already have serendipitous X-ray observations from Chandra or XMM-Newton, and at least 100000 quasars with UV and X-ray data will be made available by the extended ROentgen Survey with an Imaging Telescope Array all-sky survey in a few years. The Euclid, Large Synoptic Survey Telescope, and Advanced Telescope for High ENergy Astrophysics surveys will further increase the sample size to at least several hundred thousand. Our simulations show that these samples will provide tight constraints on the cosmological parameters and will allow us to test for possible deviations from the standard model with higher precision than is possible today.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/643/A4
- Title:
- ALPINE-ALMA [CII] survey. IR luminosity
- Short Name:
- J/A+A/643/A4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present dust attenuation properties of spectroscopically confirmed star forming galaxies on the main sequence at a redshift of ~4.4-5.8. Our analyses are based on the far infrared continuum observations of 118 galaxies at rest-frame 158 {mu}m obtained with the Atacama Large Millimeter Array (ALMA) Large Program to INvestigate [CII] at Early times (ALPINE). We study the connection between the ultraviolet (UV) spectral slope ({beta}), stellar mass (M*), and infrared excess (IRX=L_IR_/L_UV_). Twenty-three galaxies are individually detected in the continuum at > 3.5{sigma} significance. We perform a stacking analysis using both detections and nondetections to study the average dust attenuation properties at z~4.4-5.8. The individual detections and stacks show that the IRX-{beta} relation at z~5 is consistent with a steeper dust attenuation curve than typically found at lower redshifts (z<4). The attenuation curve is similar to or even steeper than that of the extinction curve of the Small Magellanic Cloud. This systematic change of the IRX-{beta} relation as a function of redshift suggests an evolution of dust attenuation properties at z>4. Similarly, we find that our galaxies have lower IRX values, up to 1dex on average, at a fixed mass compared to previously studied IRX-M* relations at z<=4, albeit with significant scatter. This implies a lower obscured fraction of star formation than at lower redshifts. Our results suggest that dust properties of UV-selected star forming galaxies at z>=4 are characterised by (i) a steeper attenuation curve than at z<=4, and (ii) a rapidly decreasing dust obscured fraction of star formation as a function of redshift. Nevertheless, even among this UV-selected sample, massive galaxies (logM*/M_{sun}_>10) at z~5-6 already exhibit an obscured fraction of star formation of ~45%, indicating a rapid build-up of dust during the epoch of reionization.
- ID:
- ivo://CDS.VizieR/J/A+A/643/A2
- Title:
- ALPINE DR1 merged catalog
- Short Name:
- J/A+A/643/A2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ALPINE-ALMA large program targets the [CII] 158um line and the far-infrared continuum in 118 spectroscopically confirmed star-forming galaxies between z=4.4 and z=5.9. It represents the first large [CII] statistical sample built in this redshift range. We present details of the data processing and the construction of the catalogs. We detected 23 of our targets in the continuum. To derive accurate infrared luminosities and obscured star formation rates, we measured the conversion factor from the ALMA 158um rest-frame dust continuum luminosity to the total infrared luminosity (LIR) after constraining the dust spectral energy distribution by stacking a photometric sample similar to ALPINE in ancillary single-dish far-infrared data. We found that our continuum detections have a median LIR of 4.4x10^11^L_{sun}_. We also detected 57 additional continuum sources in our ALMA pointings. They are at lower redshift than the ALPINE targets, with a mean photometric redshift of 2.5+/-0.2. We measured the 850um number counts between 0.35 and 3.5mJy, improving the current interferometric constraints in this flux density range. We found a slope break in the number counts around 3mJy with a shallower slope below this value. More than 40% of the cosmic infrared background is emitted by sources brighter than 0.35mJy. Finally, we detected the [CII] line in 75 of our targets. Their median [CII] luminosity is 4.8x108L_{sun}_ and their median full width at half maximum is 252km/s. After measuring the mean obscured SFR in various [CII] luminosity bins by stacking ALPINE continuum data, we find a good agreement between our data and the local and predicted SFR-L[CII] relations of De Looze et al. (2014A&A...568A..62D) and Lagache et al. (2018A&A...609A.130L).
- ID:
- ivo://CDS.VizieR/J/ApJ/900/9
- Title:
- AMIGA: The Circumgalactic Medium of Andromeda
- Short Name:
- J/ApJ/900/9
- Date:
- 14 Mar 2022 07:38:05
- Publisher:
- CDS
- Description:
- Project AMIGA (Absorption Maps In the Gas of Andromeda) is a survey of the circumgalactic medium (CGM) of Andromeda (M31, R_vir_~300kpc) along 43 QSO sightlines at impact parameters 25<~R<~569kpc (25 at R<~R_vir_). We use ultraviolet absorption measurements of SiII, SiIII, SiIV, CII, and CIV from the Hubble Space Telescope/Cosmic Origins Spectrograph and OVI from the Far Ultraviolet Spectroscopic Explorer to provide an unparalleled look at how the physical conditions and metals are distributed in the CGM of M31. We find that SiIII and OVI have a covering factor near unity for R<~1.2R_vir_ and <~1.9R_vir_, respectively, demonstrating that M31 has a very extended ~104-105.5K ionized CGM. The metal and baryon masses of the 104-105.5K CGM gas within R_vir_ are >~108 and >~4x1010 (Z/0.3Z{sun})-1M{sun}, respectively. There is not much azimuthal variation in the column densities or kinematics, but there is with R. The CGM gas at R<~0.5R_vir_ is more dynamic and has more complicated, multiphase structures than at larger radii, perhaps a result of more direct impact of galactic feedback in the inner regions of the CGM. Several absorbers are projected spatially and kinematically close to M31 dwarf satellites, but we show that those are unlikely to give rise to the observed absorption. Cosmological zoom simulations of ~L* galaxies have OVI extending well beyond R_vir_ as observed for M31 but do not reproduce well the radial column density profiles of the lower ions. However, some similar trends are also observed, such as the lower ions showing a larger dispersion in column density and stronger dependence on R than higher ions. Based on our findings, it is likely that the Milky Way has a ~104-105.5K CGM as extended as for M31 and their CGM (especially the warm-hot gas probed by OVI) are overlapping.
- ID:
- ivo://CDS.VizieR/J/AJ/143/28
- Title:
- Analysis of B6-A9 stars from INES UV spectra
- Short Name:
- J/AJ/143/28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Main-sequence (MS) and giant late-B and early-A type stars are the best targets for searching for nearby interstellar (IS) SiIV and CIV resonance lines because they are not able to produce them, either in atmospheric layers or in their circumstellar environment, and because many stars of these spectral types are nearby and located in the local interstellar medium (LISM). In addition, the use of certain stars hotter than B6 can lead to misinterpretations (e.g., alpha Arae). This work analyzes the reliable Short-Wavelength Prime (SWP) high-resolution UV spectra of 558 B6-A9 type stars observed by the International Ultraviolet Explorer at distances lower than 400pc from the Sun. For the first time, this work utilizes the entire INES database to extract stellar and IS information in a systematic way from homogeneous data. Stars were classified into seven groups: normal (MS and subgiant), giant, peculiar, emission line, Algols, pre-main sequence or Herbig Ae/Be, and shell stars. Only 10 normal stars, located beyond 90pc, show weak SiIV and CIV absorptions and are clustered around the direction of Sco-Cen, while 85 located closer than 90pc, as well as another 89 beyond 90pc, do not show any absorptions at all.
- ID:
- ivo://CDS.VizieR/J/A+A/432/1063
- Title:
- Analysis of inner solar corona in Extreme-UV
- Short Name:
- J/A+A/432/1063
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the differential emission measure (DEM) of a `quiet Sun' area observed in the extreme ultraviolet at normal incidence by the Coronal Diagnostic Spectrometer (CDS) on the SOHO spacecraft. The data used for this work were taken using the NISAT_S_ observing sequence. This takes the full wavelength ranges from both the NIS channels (308-381{AA} and 513-633{AA}) with the 2 arcsec by 240 arcsec slit, which is the narrowest slit available, yielding the best spectral resolution. In this work we contrast the DEM from subregions of 2*80arcsec^2^ with that obtained from the mean spectrum of the whole raster (20*240arcsec^2^). We find that the DEM maintains essentially the same shape in the subregions, differing by a constant factor between 0.5 and 2 from the mean DEM, except in areas were the electron density is below 2*10^7^cm^-3^ and downflow velocities of 50km/s are found in the transition region. Such areas are likely to contain plasma departing from ionisation equilibrium, violating the basic assumptions underlying the DEM method. The comparison between lines of Li-like and Be-like ions may provide further evidence of departure from ionisation equilibrium. We find also that line intensities tend to be lower where velocities of the order of 30km/s or higher are measured in transition region lines. The DEM analysis is also exploited to improve the line identification performed by Brooks et al. (1999A&A...347..277B) and to investigate possible elemental abundance variations from region to region. We find that the plasma has composition close to photospheric in all the subregions examined.
- ID:
- ivo://CDS.VizieR/J/ApJS/211/27
- Title:
- An atlas of FUV spectra of 31 Cyg
- Short Name:
- J/ApJS/211/27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The {zeta} Aurigae system 31 Cygni (K4 Ib + B4 V) was observed by the FUSE satellite during total eclipse and at three phases during chromospheric eclipse. We present the coadded, calibrated spectra and atlases with line identifications. During total eclipse, emission from high ionization states (e.g., Fe III and Cr III) shows asymmetric profiles redshifted from the systemic velocity, while emission from lower ionization states (e.g., Fe II and O I) appears more symmetric and is centered closer to the systemic velocity. Absorption from neutral and singly ionized elements is detected during chromospheric eclipse. Late in chromospheric eclipse, absorption from the K star wind is detected at a terminal velocity of ~80km/s. These atlases will be useful for interpreting the far-UV spectra of other {zeta} Aur systems, as the observed FUSE spectra of 32 Cyg, KQ Pup, and VV Cep during chromospheric eclipse resemble that of 31 Cyg.
- ID:
- ivo://CDS.VizieR/III/157
- Title:
- An Ultraviolet Atlas of Quasar and Blazar Spectra
- Short Name:
- III/157
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This atlas contains the ultraviolet spectra of 70 quasars, blazars, and Seyfert 1 galaxies that were produced by combining over 100 low resolution spectra from the International Ultraviolet Explorer (IUE) data archive. The spectra have been extracted with an optimal algorithm (see Kinney et al. 1991) and co-added to produce spectra with the best possible signal-to-noise ratio.
- ID:
- ivo://CDS.VizieR/J/ApJ/727/83
- Title:
- A panchromatic study of BLAST counterparts
- Short Name:
- J/ApJ/727/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carry out a multi-wavelength study of individual galaxies detected by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST) and identified at other wavelengths, using data spanning the radio to the ultraviolet (UV). We develop a Monte Carlo method to account for flux boosting, source blending, and correlations among bands, which we use to derive deboosted far-infrared (FIR) luminosities for our sample. We estimate total star-formation rates (SFRs) for BLAST counterparts with z<=0.9 by combining their FIR and UV luminosities. We assess that about 20% of the galaxies in our sample show indication of a type 1 active galactic nucleus, but their submillimeter emission is mainly due to star formation in the host galaxy. We compute stellar masses for a subset of 92 BLAST counterparts; these are relatively massive objects, with a median mass of ~10^11^M_{sun}_, which seem to link the 24um and Submillimetre Common-User Bolometer Array (SCUBA) populations, in terms of both stellar mass and star formation activity.
- ID:
- ivo://CDS.VizieR/J/ApJ/840/81
- Title:
- A^3^{Pi}-X^3^{Sigma}^-^ transitions of OH+
- Short Name:
- J/ApJ/840/81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The OH^+^ ion is of critical importance to the chemistry in the interstellar medium and is a prerequisite for the generation of more complex chemical species. Submillimeter and ultraviolet observations rely on high quality laboratory spectra. Recent measurements of the fundamental vibrational band and previously unanalyzed Fourier transform spectra of the near-ultraviolet A^3^{Pi}-X^3^{Sigma}^-^ electronic spectrum, acquired at the National Solar Observatory (NSO) at Kitt Peak in 1989, provide an excellent opportunity to perform a global fit of the available data. These new optical data are approximately four times more precise as compared to the previous values. The fit to the new data provides updated molecular constants, which are necessary to predict the OH^+^ transition frequencies accurately to support future observations. These new constants are the first published using the modern effective Hamiltonian for a linear molecule. These new molecular constants allow for easy simulation of transition frequencies and spectra using the PGOPHER program. The new constants improve simulations of higher J-value infrared transitions, and represent an improvement of an order of magnitude for some constants pertaining to the optical transitions.
