Using the 770 ks XMM-Newton survey of the Lockman Hole field in combination with extensive optical identifications of the AGN population, we derive an average rest-frame spectrum of AGN types-1 and ...2. The most prominent feature in the averaged spectrum is a strong fluorescent Fe line. In both type-1 and type-2 AGN, a clear relativistic line profile is revealed. A laor line profile with an inner disk radius smaller than the last stable orbit of a Schwarzschild black hole is most consistent with the data, indicating that the average supermassive black hole has significant spin. Equivalent widths of the broad relativistic lines range between 400-600 eV. We used the disk reflection model to compare the observed strength of the line with the amplitude of the reflection component, concluding that to consistently describe the observations the average iron abundance should be about three times the solar value.
The second catalogue of
Planck
Sunyaev-Zeldovich (SZ) sources, hereafter PSZ2, represents the largest galaxy cluster sample selected by means of their SZ signature in a full-sky survey. Using ...telescopes at the Canary Island observatories, we conducted the long-term observational program 128- MULTIPLE-16/15B (hereafter LP15), a large and complete optical follow-up campaign of all the unidentified PSZ2 sources in the northern sky, with declinations above −15° and no correspondence in the first
Planck
catalogue PSZ1. This paper is the third and last in the series of LP15 results, after Streblyanska et al. (2019, A&A, 628, A13) and Aguado-Barahona et al. (2019, A&A, 631, A148), and presents all the spectroscopic observations of the full program. We complement these LP15 spectroscopic results with Sloan Digital Sky Survey archival data and other observations from a previous program (ITP13-08), and present a catalogue of 388 clusters and groups of galaxies including estimates of their velocity dispersion. The majority of them (356) are optical counterparts of PSZ2 sources. A subset of 297 of those clusters are used to construct the
M
SZ
−
M
dyn
scaling relation based on the estimated SZ mass from
Planck
measurements and our dynamical mass estimates. We discuss and correct for different statistical and physical biases in the estimation of the masses, such as the Eddington bias when estimating
M
SZ
and the aperture and the number of galaxies used to calculate
M
dyn
. The SZ-to-dynamical mass ratio for those 297 PSZ2 clusters is (1 −
B
) = 0.80 ± 0.04 (stat) ± 0.05 (sys), with only marginal evidence for a possible mass dependence for this factor. Our value is consistent with previous results in the literature, but is associated with a significantly smaller uncertainty due to the use of the largest sample size for this type of study.
Context.
The second legacy catalog of
Planck
Sunyaev–Zeldovich (SZ) sources, hereafter PSZ2, provides the largest galaxy cluster sample selected by means of the SZ signature of the clusters in a full ...sky survey. In order to fully characterize this PSZ2 sample for cosmological studies, all the members should be validated and the physical properties of the clusters, including mass and redshift, should be derived. However, at the time of its publication, roughly 21% of the 1653 PSZ2 members had no known counterpart at other wavelengths.
Aims.
Here, we present the second and last year of observations of our optical follow-up program 128-MULTIPLE-16/15B (hereafter LP15), which has been developed with the aim of validating all the unidentified PSZ2 sources in the northern sky with declinations higher than −15° that have no correspondence in the first
Planck
catalog PSZ1. The description of the program and the first year of observations have been presented previously.
Methods.
The LP15 program was awarded 44 observing nights that were spread over two years with the
Isaac Newton
Telescope (INT), the Telescopio Nazionale
Galileo
(TNG), and the Gran Telescopio Canarias (GTC), all at Roque de los Muchachos Observatory (La Palma). Following the same method as described previously, we performed deep optical imaging for more than 200 sources with the INT and spectroscopy for almost 100 sources with the TNG and GTC at the end of the LP15 program. We adopted robust confirmation criteria based on velocity dispersion and richness estimates for the final classification of the new galaxy clusters as the optical counterparts of the PSZ2 detections.
Results.
Here, we present the observations of the second year of LP15, as well as the final results of the program. The full LP15 sample comprises 190 previously unidentified PSZ2 sources. Of these, 106 objects were studied before, while the remaining sample (except for 6 candidates) has been completed in the second year and is discussed here. In addition to the LP15 sample, we here study 42 additional PSZ2 objects that were originally validated as real clusters because they matched a WISE or PSZ1 counterpart, but they had no measured spectroscopic redshift. In total, we confirm the optical counterparts for 81 PSZ2 sources after the full LP15 program, 55 of them with new spectroscopic information. Forty of these 81 clusters are presented in this paper. After the LP15 observational program the purity of the PSZ2 catalog has increased from 76.7% originally to 86.2%. In addition, we study the possible reasons for false detection, and we report a clear correlation between the number of unconfirmed sources and galactic thermal dust emission.
We present the velocity dispersion and dynamical mass estimates for 270 galaxy clusters included in the first
Planck
Sunyaev-Zeldovich (SZ) source catalogue, the PSZ1. Part of the results presented ...here were achieved during a two-year observational program, the ITP, developed at the Roque de los Muchachos Observatory (La Palma, Spain). In the ITP we carried out a systematic optical follow-up campaign of all the 212 unidentified PSZ1 sources in the northern sky that have a declination above −15° and are without known counterparts at the time of the publication of the catalogue. We present for the first time the velocity dispersion and dynamical mass of 58 of these ITP PSZ1 clusters, plus 35 newly discovered clusters that are not associated with the PSZ1 catalogue. Using Sloan Digital Sky Survey archival data, we extend this sample, including 212 already confirmed PSZ1 clusters in the northern sky. Using a subset of 207 of these galaxy clusters, we constrained the
M
SZ
–
M
dyn
scaling relation, finding a mass bias of (1 −
B
) = 0.83 ± 0.07(stat) ± 0.02(sys). We show that this value is consistent with other results in the literature that were obtained with different methods (X-ray, dynamical masses, or weak-lensing mass proxies). This result cannot dissolve the tension between primordial cosmic microwave background anisotropies and cluster number counts in the Ω
M
–
σ
8
plane.
We present EMIR, a powerful near-infrared (NIR) camera and multi-object spectrograph (MOS) installed at the Nasmyth focus of the 10.4 m GTC. EMIR was commissioned in mid-2016 and is offered as a ...common-user instrument. It provides spectral coverage of 0.9–2.5 µm over a field of view (FOV) of 6.67′ × 6.67′ in imaging mode, and 6.67′ × 4′ in spectroscopy. EMIR delivers up to 53 spectra of different objects thanks to a robotic configurable cold slit mask system that is located inside the cryogenic chamber, allowing rapid reconfiguration of the observing mask. The imaging mode is attained by moving all bars outside the FOV and then leaving an empty space in the GTC focal surface. The dispersing suite holds three large pseudo-grisms, formed by the combination of high-efficiency FuSi ion-etched ruled transmission grating sandwiched between two identical ZnSe prisms, plus one standard replicated grism. These dispersing units offer the spectral recording of an atmospheric window
J
,
H, K
in a single shot with resolving powers of 5000, 4250, 4000, respectively for a nominal slit width of 0.6″, plus the combined bands
Y J
or
HK
, also in a single shot, with resolution of ~1000. The original Hawaii2 FPA detector, which is prone to instabilities that add noise to the signal, is being replaced by a new Hawaii2RG detector array, and is currently being tested at the IAC. This paper presents the most salient features of the instrument, with emphasis on its observing capabilities and the functionality of the configurable slit unit. Sample early science data is also shown.
Aims
. The second catalogue of
Planck
Sunyaev–Zeldovich (SZ) sources, hereafter PSZ2, is the largest sample of galaxy clusters selected through their SZ signature in the full sky. At the time of ...publication, 21% of these objects had no known counterpart at other wavelengths. Using telescopes at the Canary Island observatories, we conducted the long-term observational programme 128-MULTIPLE-16/15B (hereafter LP15), a large and complete optical follow-up campaign of all the unidentified PSZ2 sources in the northern sky, with declinations above −15° and no correspondence in the first
Planck
catalogue PSZ1. The main aim of LP15 is to validate all those SZ cluster candidates, and to contribute to the characterization of the actual purity and completeness of full
Planck
SZ sample. In this paper, we describe the full programme and present the results of the first year of observations.
Methods
. The LP15 programme was awarded 44 observing nights, spread over two years in three telescopes at the Roque de los Muchachos Observatory. The full LP15 sample comprises 190 previously unidentified PSZ2 sources. For each target, we performed deep optical imaging and spectroscopy. Our validation procedure combined this optical information with SZ emission as traced by the publicly available
Planck
Compton
y
-maps. The final classification of the new galaxy clusters as optical counterparts of the SZ signal is established according to several quantitative criteria based on the redshift, velocity dispersion, and richness of the clusters.
Results
. This paper presents the detailed study of 106 objects out of the LP15 sample, corresponding to all the observations carried out during the first year of the programme. We confirmed the optical counterpart for 41 new PSZ2 sources, 31 of them being validated using also velocity dispersion based on our spectroscopic information. This is the largest dataset of newly confirmed PSZ2 sources without any previous optical information. All the confirmed counterparts are rich structures (i.e. they show high velocity dispersion), and are well aligned with the nominal
Planck
coordinates (i.e. ∼70% of them are located at less than 3′ distance). In total, 65 SZ sources are classified as unconfirmed, 57 of them being due to the absence of an optical over-density, and eight of them due to a weak association with the observed SZ decrement. Most of the sources with no optical counterpart are located at low galactic latitudes and present strong galactic cirrus in the optical images, the dust contamination being the most probable explanation for their inclusion in the PSZ2 catalogue.
The Cluster HEritage project with
XMM-Newton
– Mass Assembly and Thermodynamics at the Endpoint of structure formation (CHEX-MATE) is a three-mega-second Multi-Year Heritage Programme to obtain X-ray ...observations of a minimally-biased, signal-to-noise-limited sample of 118 galaxy clusters detected by
Planck
through the Sunyaev–Zeldovich effect. The programme, described in detail in this paper, aims to study the ultimate products of structure formation in time and mass. It is composed of a census of the most recent objects to have formed (Tier-1: 0.05 <
z
< 0.2; 2 × 10
14
M
⊙
<
M
500
< 9 × 10
14
M
⊙
), together with a sample of the highest mass objects in the Universe (Tier-2:
z
< 0.6;
M
500
> 7.25 × 10
14
M
⊙
). The programme will yield an accurate vision of the statistical properties of the underlying population, measure how the gas properties are shaped by collapse into the dark matter halo, uncover the provenance of non-gravitational heating, and resolve the major uncertainties in mass determination that limit the use of clusters for cosmological parameter estimation. We will acquire X-ray exposures of uniform depth, designed to obtain individual mass measurements accurate to 15 − 20% under the hydrostatic assumption. We present the project motivations, describe the programme definition, and detail the ongoing multi-wavelength observational (lensing, SZ, radio) and theoretical effort that is being deployed in support of the project.
Strong gravitational lenses are now being routinely discovered in wide-field surveys at (sub-)millimeter wavelengths. We present Submillimeter Array (SMA) high-spatial resolution imaging and ...Gemini-South and Multiple Mirror Telescope optical spectroscopy of strong lens candidates discovered in the two widest extragalactic surveys conducted by the Herschel Space Observatory: the Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS) and the Herschel Multi-tiered Extragalactic Survey (HerMES). From a sample of 30 Herschel sources with S 500 > 100 mJy, 21 are strongly lensed (i.e., multiply imaged), 4 are moderately lensed (i.e., singly imaged), and the remainder require additional data to determine their lensing status. We apply a visibility-plane lens modeling technique to the SMA data to recover information about the masses of the lenses as well as the intrinsic (i.e., unlensed) sizes (r half) and far-infrared luminosities (L FIR) of the lensed submillimeter galaxies (SMGs). The sample of lenses comprises primarily isolated massive galaxies, but includes some groups and clusters as well. Several of the lenses are located at z lens > 0.7, a redshift regime that is inaccessible to lens searches based on Sloan Digital Sky Survey spectroscopy. The lensed SMGs are amplified by factors that are significantly below statistical model predictions given the 500 μm flux densities of our sample. We speculate that this may reflect a deficiency in our understanding of the intrinsic sizes and luminosities of the brightest SMGs. The lensed SMGs span nearly one decade in L FIR (median L FIR = 7.9 × 1012 L ⊙) and two decades in FIR luminosity surface density (median ΣFIR = 6.0 × 1011 L ⊙ kpc-2). The strong lenses in this sample and others identified via (sub-)mm surveys will provide a wealth of information regarding the astrophysics of galaxy formation and evolution over a wide range in redshift. IMAGING OF HERSCHEL
Measuring the population of obscured quasars is one of the key issues in understanding the evolution of active galactic nuclei (AGNs). With a redshift completeness of 99%, the X-ray sources detected ...in the Chandra Deep Field South (CDF-S) provide the best sample for this issue. In this paper, we study the population of obscured quasars in CDF-S by choosing the 4--7 keV selected sample, which is less biased by the intrinsic X-ray absorption. The 4-7 keV band-selected samples also filter out most of the X-ray-faint sources with too few counts, for which the measurements of N sub(H) and L sub(X) have very large uncertainties. Simply adopting the best-fit L sub(2-10 keV) and N sub(H), we find that 71% c 19% (20 out of 28) of the quasars (with intrinsic L sub(2-10 keV) > 10 super(44) ergs s super(-1)) are obscured with N sub(H) > 10 super(22) cm super(-2). Taking into account the uncertainties in the measurements of both N sub(H) and L sub(x), conservative lower and upper limits for the fraction are 54% (13 out 24) and 84% (31 out 37). In the Chandra Deep Field North, the number is 29%; however, this is mainly due to the redshift incompleteness. We estimate a fraction of 650%-63% after correcting for the redshift incompleteness with a straightforward approach. Our results robustly confirm the existence of a large population of obscured quasars.
We present a method for selecting z \textgreater 4 dusty, star-forming galaxies (DSFGs) using Herschel/Spectral and Photometric Imaging Receiver 250/350/500 mu m flux densities to search for red ...sources. We apply this method to 21 deg(2) of data from the HerMES survey to produce a catalog of 38 high-z candidates. Follow-up of the first five of these sources confirms that this method is efficient at selecting high-z DSFGs, with 4/5 at z = 4.3-6.3 (and the remaining source at z = 3.4), and that they are some of the most luminous dusty sources known. Comparison with previous DSFG samples, mostly selected at longer wavelengths (e. g., 850 mu m) and in single-band surveys, shows that our method is much more efficient at selecting high-z DSFGs, in the sense that a much larger fraction are at z \textgreater 3. Correcting for the selection completeness and purity, we find that the number of bright (S-500 (mu m) \textgreater= 30 mJy), red Herschel sources is 3.3 +/- 0.8 deg(-2). This is much higher than the number predicted by current models, suggesting that the DSFG population extends to higher redshifts than previously believed. If the shape of the luminosity function for high-z DSFGs is similar to that at z similar to 2, rest-frame UV based studies may be missing a significant component of the star formation density at z = 4-6, even after correction for extinction.
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