- ID:
- ivo://nasa.heasarc/bootesdf
- Title:
- Bootes Deep Field WSRT 1.4-GHz Source Catalog
- Short Name:
- Bootes
- Date:
- 14 Feb 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This radio source catalog is the result of deep (16x12 hour) Westerbork Synthesis Radio Telescope (WSRT) observations of the approximately 7 square degree Bootes Deep Field, centered at an RA and Declination (J2000) of 14 hr 32 min 5.75 sec, +34 deg 16 arcmin 47.5 arcsec. The survey consisted of 42 discrete pointings, with enough overlap to ensure a uniform sensitivity across the entire field, and with a limiting sensitivity of 28 microJansky (1 sigma rms). The catalog consists of 3172 distinct sources detected with a significance of 5 sigma or greater, of which 316 are resolved by the 13 x 27 arcsec beam. This database table was created by the HEASARC in December 2001 based on the a data file obtained from the authors' FTP site (no longer available). It was modified slightly in March 2011 (using the CDS data file <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/123/1784/catalog.dat">https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/123/1784/catalog.dat</a>) to make the source names adhere to the naming convention of the Dictionary of Nomenclature of Celestial Objects. This is a service provided by NASA HEASARC .
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- ID:
- ivo://CDS.VizieR/J/A+A/620/A74
- Title:
- Bootes field deep LOFAR 150MHz imaging
- Short Name:
- J/A+A/620/A74
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a deep survey (with a central rms of 55uJy) with the LOw Frequency ARray (LOFAR) at 120-168MHz of the Bootes field, with an angular resolution of 3.98"x6.45", and obtained a sample of 10091 radio sources (5{sigma} limit) over an area of 20deg^2^. The astrometry and flux scale accuracy of our source catalog is investigated. The resolution bias, incompleteness and other systematic effects that could affect our source counts are discussed and accounted for. The derived 150MHz source counts present a flattening below sub-mJy flux densities, that is in agreement with previous results from high- and low- frequency surveys. This flattening has been argued to be due to an increasing contribution of star-forming galaxies and faint active galactic nuclei. Additionally, we use our observations to evaluate the contribution of cosmic variance to the scatter in source counts measurements. The latter is achieved by dividing our Bootes mosaic into 10 non-overlapping circular sectors, each one with an approximate area of 2deg^2^. The counts in each sector are computed in the same way as done for the entire mosaic. By comparing the induced scatter with that of counts obtained from depth observations scaled to 150MHz, we find that the 1{sigma} scatter due to cosmic variance is larger than the Poissonian errors of the source counts, and it may explain the dispersion from previously reported depth source counts at flux densities S<1mJy. This work demonstrates the feasibility of achieving deep radio imaging at low-frequencies with LOFAR.
- ID:
- ivo://nasa.heasarc/boof153mhz
- Title:
- Bootes Field GMRT 153-MHz Source Catalog
- Short Name:
- BOOF153MHZ
- Date:
- 14 Feb 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors obtained deep, high-resolution radio interferometric observations at 153 MHz to complement the extensively studied NOAO Bootes field. In their paper, they provide a description of the observations, data reduction and source catalog construction. From their single-pointing GMRT observation of ~12 hours, they obtained a high-resolution (26" x 22") image of ~11.3 square degrees, fully covering the Bootes field region and beyond. The image has a central noise level of ~1.0 mJy beam<sup>-1</sup>, which rises to 2.0 - 2.5 mJy beam<sup>-1</sup> at the field edge, placing it amongst the deepest ~150 MHz surveys to date. The catalog of 598 extracted sources is estimated to be ~92% complete for > 10 mJy sources, while the estimated contamination by false detections is < 1%. The low rms positional uncertainty of 1.24" facilitates accurate matching against catalogs at optical, infrared and other wavelengths. Differential source counts were determined down to < ~10 mJy. The authors find no evidence for flattening of the counts towards lower flux densities as observed in deep radio surveys at higher frequencies, suggesting that their catalog is dominated by the classical radio-loud AGN population that explains the counts at higher flux densities. Combination with available deep 1.4 GHz observations yields an accurate determination of spectral indices for 417 sources down to the lowest 153 MHz flux densities, of which 16 have ultra-steep spectra with spectral indices below -1.3. The authors confirm that flattening of the median spectral index towards low flux densities also occurs at this frequency. The detection fraction of the radio sources in the NIR K<sub>s</sub>-band is found to drop with radio spectral index, which is in agreement with the known correlation between spectral index and redshift for brighter radio sources. This table contains the list of 598 153-MHz sources detected in the GMRT observation and their properties at this frequency. There are a number of other tables of objects in the Bootes field made at other frequencies: <pre> HEASARC Table | Title | Reference BOOTESDF | 1.4GHz imaging of the Bootes field | de Vries+ 2002,AJ,123,1784 LALABOOCXO | LALA Bootes field X-ray source catalog | Wang+ 2004,AJ,127,213 --- | Faint radio sources in NOAO Bootes field | Wrobel+ 2005,AJ,130,923 --- | 16um sources in the NOAO Bootes field | Kasliwal+ 2005,ApJ,634,L1 XBOOTES | X-ray survey of the NDWFS Bootes field | Kenter+ 2005,ApJS,161,9 XBOOTESOID | Optical counterparts in the NDWFS Bootes | Brand+ 2006,ApJ,64,140 | field | </pre> This table was created by the HEASARC in December 2011 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/535/A38">CDS Catalog J/A+A/535/A38</a> file table3.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/MNRAS/460/2385
- Title:
- Bootes field LOFAR 150-MHz observations
- Short Name:
- J/MNRAS/460/2385
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first wide area (19 deg^2^), deep (~=120-150 {mu}Jy/beam), high-resolution (5.6x7.4-arcsec) LOFAR High Band Antenna image of the Bootes field made at 130-169MHz. This image is at least an order of magnitude deeper and 3-5 times higher in angular resolution than previously achieved for this field at low frequencies. The observations and data reduction, which includes full direction-dependent calibration, are described here. We present a radio source catalogue containing 6276 sources detected over an area of 19deg^2^, with a peak flux density threshold of 5{sigma}. As the first thorough test of the facet calibration strategy, introduced by van Weeren et al. (2016ApJS..223....2V), we investigate the flux and positional accuracy of the catalogue. We present differential source counts that reach an order of magnitude deeper in flux density than previously achieved at these low frequencies, and show flattening at 150-MHz flux densities below 10 mJy associated with the rise of the low flux density star-forming galaxies and radio-quiet AGN.
- ID:
- ivo://CDS.VizieR/J/A+A/653/A74
- Title:
- Bootes field X-ray/non-X-ray sources
- Short Name:
- J/A+A/653/A74
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We use X-ray active galactic nuclei (AGN) observed by the Chandra X-ray Observatory within the 9.3deg^2^ Bootes field of the NDWFS to study whether there is a correlation between X-ray luminosity (LX) and star formation rate (SFR) of the host galaxy, at 0.5<z<2.0, with respect to the position of the galaxy to the main sequence (SFRnorm). About half of the sources in the X-ray sample have spectroscopic redshifts. We also construct a reference galaxy catalogue. For both datasets we use photometric data from the optical to the far-infrared compiled by the HELP project, and apply spectral energy distribution (SED) fitting, using the X-CIGALE code. We exclude quiescent sources from both the X-ray and the reference samples. We also account for the mass completeness of our dataset, in different redshifts bins. Our analysis highlights the importance of studying the SFR-LX relation in a uniform manner, taking into account systematics and selection effects. Our results suggest, in less massive galaxies (log[M*(M_{sun}_)]~11), that an AGN enhances the SFR of the host galaxy by 50% compared to non-AGN systems. A flat relation is observed for the most massive galaxies. The SFRnorm does not evolve with redshift. The results, although tentative, are consistent with a scenario where, in less massive systems, both AGN and star formation are fed by cold gas supplied by a merger event. In more massive galaxies the flat relation could be explained by a different supermasssive black hole (SMBH) fuelling mechanism that is decoupled from the star formation of the host galaxy (e.g. hot diffuse gas). Finally, we compare the host galaxy properties of X-ray absorbed and unabsorbed sources. Our results show no difference, which suggests that X-ray absorption is not linked with the properties of the galaxy.
- ID:
- ivo://CDS.VizieR/J/MNRAS/471/629
- Title:
- Bootes-HiZELS. Em-line galaxies at z=0.4-4.7
- Short Name:
- J/MNRAS/471/629
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sample of ~1000 emission-line galaxies at z=0.4-4.7 from the ~0.7deg^2^ High-z Emission-Line Survey in the Bootes field identified with a suite of six narrow-band filters at ~=0.4-2.1{mu}m. These galaxies have been selected on their Ly{alpha} (73), [OII] (285), H{beta}/[OIII] (387) or H{alpha} (362) emission line, and have been classified with optical to near-infrared colours. A subsample of 98 sources have reliable redshifts from multiple narrow-band (e.g. [OII]-H{alpha}) detections and/or spectroscopy. In this survey paper, we present the observations, selection and catalogues of emitters. We measure number densities of Ly{alpha}, [OII], H{beta}/[OIII] and H{alpha} and confirm strong luminosity evolution in star-forming galaxies from z~0.4 to ~5, in agreement with previous results. To demonstrate the usefulness of dual-line emitters, we use the sample of dual [OII]-H{alpha} emitters to measure the observed [OII]/H{alpha} ratio at z=1.47. The observed [OII]/H{alpha} ratio increases significantly from 0.40+/-0.01 at z=0.1 to 0.52+/-0.05 at z=1.47, which we attribute to either decreasing dust attenuation with redshift, or due to a bias in the (typically) fibre measurements in the local Universe that only measure the central kpc regions. At the bright end, we find that both the H{alpha} and Ly{alpha} number densities at z~=2.2 deviate significantly from a Schechter form, following a power law. We show that this is driven entirely by an increasing X-ray/active galactic nucleus fraction with line luminosity, which reaches ~=100 per cent at line luminosities L>=3x10^44^erg/s.
1987. Boo Void survey
- ID:
- ivo://CDS.VizieR/J/ApJ/314/493
- Title:
- Boo Void survey
- Short Name:
- J/ApJ/314/493
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In an earlier paper we inferred, from the distribution of galaxy redshifts in three small fields ~30{deg} apart, the existence of a 10^6^Mpc^3^ void in the distribution of galaxies in the constellation of Bootes. In this paper, we describe a redshift survey undertaken to test that hypothesis. Galaxies were selected by eye from 283 small fields distributed between the three original fields, and redshifts were measured for 239 of them. We confirm the existence of a large, roughly spherical void, of radius 62Mpc, centered at {alpha}=14h50, {delta}=+46{deg}, v=15500km/s. The low density of this region is of high statistical significance and does not appear easily reconcilable with any of the popular models for the growth of structure in the universe. This void does contain some unusual galaxies characterized by strong, high-excitation emission spectra, but not in sufficient numbers to compensate for the absence of more usual objects.
- ID:
- ivo://CDS.VizieR/I/228
- Title:
- Bordeaux AC Zone Data Reduced to ACRS
- Short Name:
- I/228
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The U.S. Naval Observatory is in the process of making new reductions of the Astrographic Catalogue (AC) using a modern reference system, the ACRS, which represents the system of the FK5. The data from the Bordeaux Zone, whose plates are centered between declinations +11 and +17 degrees (eq. 1900), have been analyzed for scale, rotation, tilt, coma, magnitude equation, radial distortion and distortions introduced by the use of reseaux in the Carte du Ciel program. The result is a positional catalog of over 223,000 stars on eq. J2000.0, epoch of observation. Additionally, all stars have been matched with the Tycho Input Catalog (revised); those numbers have been added for additional identification purposes.
- ID:
- ivo://CDS.VizieR/J/A+A/559/A100
- Title:
- Boron isoelectronic sequence data
- Short Name:
- J/A+A/559/A100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Relativistic configuration interaction (RCI) calculations are performed for 291 states belonging to the configurations 1s^2^2s^2^2p, 1s^2^2s2p^2^, 1s^2^2p^3^, 1s^2^2s^2^3l, 1s^2^2s2p3l, 1s^2^2p^2^3l, 1s^2^2s^2^4l', 1s^2^2s2p4l', and 1s^2^2p^2^4l' (l=0, 1, 2 and l'=0, 1, 2, 3) in boronlike ions Si X and Ti XVIII to Cu XXV. Electron correlation effects are represented in the wave functions by large configuration state function (CSF) expansions. States are transformed from j j-coupling to LS -coupling, and the LS -percentage compositions are used for labeling the levels. Radiative electric dipole transition rates are given for all ions, leading to massive data sets. Calculated energy levels are compared with other theoretical predictions and crosschecked against the Chianti database, NIST recommended values, and other observations. The accuracy of the calculations are high enough to facilitate the identification of observed spectral lines.
- ID:
- ivo://CDS.VizieR/J/A+A/455/1157
- Title:
- Boron-like Fe XXII transition probabilities
- Short Name:
- J/A+A/455/1157
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Energy levels and the corresponding transition probabilities as well as oscillator strengths and line strengths for allowed (E1) and forbidden (E2, M1) transitions among the lowest 407 levels of boron-like Fe XXII are presented. Calculations were performed using the multiconfigurational Dirac-Fock GRASP code.
