Cosmic evolution of supermassive black holes: A view into the next two decades

Astro2020 Science White Paper: et al.The discoveries made over the past 20 years by Chandra and XMM-Newton surveys in conjunction with multiwavelength imaging and spectroscopic data available in the same fields have significantly changed the view of the supermassive black hole (SMBH) and galaxy connection. These discoveries have opened up several exciting questions that are beyond the capabilities of current X-ray telescopes and will need to be addressed by observatories in the next two decades. As new observatories peer into the early Universe, we will begin to understand the physics and demographics of SMBH infancy (at z > 6) and investigate the influence of their accretion on the formation of the first galaxies (§ 2.1). We will also be able to understand the accretion and evolution over the cosmic history (at z ∼1–6) of the full population of black holes in galaxies, including low accretion rate, heavily obscured AGNs at luminosities beyond the reach of current X-ray surveys (§2.2 and §2.3), enabling us to resolve the connection between SMBH growth and their environment

The X-ray luminous galaxies optically classified as star forming are mostly narrow line Seyfert 1 s

[Context]: The optical and ultraviolet emission lines of galaxies are widely used to distinguish star-forming (SF) galaxies from active galactic nuclei (AGNs). However, this type of diagnostic has some associated uncertainties, because AGNs can be of low luminosity and/or heavily obscured, and the optical emission lines may be dominated by a stellar component. On the other hand, and despite its limitations, X-ray emission can be used as a reliable tracer of luminous AGNs. Several well-studied examples exist where the optical diagnostics are indicative of SF galaxy, but the X-ray properties reveal the presence of an AGN. [Aims]: We aim to characterize the nature of galaxies whose optical emission line diagnostics are consistent with star formation, but whose X-ray properties strongly point towards the presence of an AGN. Understanding these sources is of particular importance in assessing the completeness of AGN samples derived from large galaxy surveys, selected solely on the basis of their optical spectral properties. [Methods]: We construct a large sample of 211 narrow emission line galaxies (NELGs, which have full widths at half maximum (FWHMs) H β emission line star-forming>, we find a bimodal distribution in which 28 have X-ray luminosities in excess of 10 42 erg/s, large thickness parameters (T = F 2-10 keV/F [OIII] > 1) and large X-ray to optical flux ratios (X/O > 0.1), while the rest are consistent with being simply starforming galaxies. Those 28 galaxies exhibit the broadest H β line widths (FWHMs from ~300 to 1200 km s -1), and their X-ray spectrum is steeper than average and often displays a soft excess. [Conclusions]: We therefore conclude that the population of X-ray luminous NELGs with optical lines consistent with those of a starforming galaxy (which represent 19% of our whole sample) is largely dominated by narrow line Seyfert 1s (NLS1s). The occurrence of such sources in the overall optically selected sample is small (<2%), hence the contamination of optically selected galaxies by NLS1s is very small. © ESO, 2012.N. Castelló-Mor gratefully acknowledges the Spanish Ministerio de Ciencia e Innovación for a pre-doctoral fellowship. N.C.-M., X.B., L.B., and F.J.C. acknowledge partial financial support from the Spanish Ministerio de Ciencia e Innovación, through project AYA2010-21490-C02-01.Peer Reviewe

Traces of co-evolution in X-ray absorbed QSOs with high SFR at z~2

Póster presentado al Workshop Star Formation Across Space and Time, celebrado en Noordwijk (Holanda) del 11 al 14 de noviembre de 2014.Peer Reviewe

HST unveils a compact mildly relativistic Broad Line Region in the candidate true type 2 NGC 3147

NGC 3147 has been considered the best case of a true type 2 AGN: an unobscured AGN, based on the unabsorbed compact X-ray continuum, which lacks a broad line region (BLR). However, the very low luminosity of NGC 3147 implies a compact BLR, which produces very broad lines, hard to detect against the dominant background host galaxy. Narrow (0.1"x0.1") slit HST spectroscopy allowed us to exclude most of the host galaxy light, and revealed an H$\alpha$ line with an extremely broad base (FWZI$\sim27\,000$ km s$^{-1}$). The line profile shows a steep cutoff blue wing and an extended red wing, which match the signature of a mildly relativistic thin accretion disk line profile. It is indeed well fit with a nearly face on thin disk, at $i\sim23^\circ$, with an inner radius at $77\pm15$ r$_g$, which matches the prediction of $62^{+18}_{-14}$ r$_g$ from the $R_{\rm BLR} \sim L^{1/2}$ relation. This result questions the very existence of true type 2 AGN. Moreover, the detection of a thin disk, which extends below 100 r$_g$ in an $L/L_{\rm Edd}\sim10^{-4}$ system, contradicts the current view of the accretion flow configuration at extremely low accretion rates.Comment: 6 pages, 3 figures, accepted for publication in MNRAS Letter

AGN surveys

Trabajo presentado al Spanish X-ray Astronomy, celebrado en Santander del 3 al 5 de junoio de 2015.The vast majority of the X-ray sources detected above the Galactic plane turn out to be Active Galactic Nuclei (AGN). Indeed, the emission of X-ray radiation is commonly taken to be the “smoking gun” evidence for the presence of an AGN, specially if the presence of significant obscuration hides it from view in the UV/optical. In this sense, it shares with the mid-IR (and the radio) the capability of uncovering otherwise hidden AGN. Significantly, the deepest X-ray observations yield the higher density of QSO to date. Large amounts of X-ray observing time have been invested in surveys of various widths and depths, in order to assemble a complete census of the AGN population, together with significant amounts of optical/near-IR spectroscopic observation time. We will review the current results, the synergies with observations at other wavelengths, and the prospect for exciting new results, including the brilliant future augured for this field with the launch of ESA’s new X-ray observatory Athena.Peer Reviewe

An X-ray-absorbed radio-quiet QSO with an intervening strong metal absorption-line system

We find evidence for significant X-ray absorption in the QSO RXJ005734.78-272827.4, along with strong absorption lines in its optical spectrum. We propose that the absorption lines are due to an intervening metal-line system at a redshift of z = 0.628, and show that this intervening system is also the probable cause of the X-ray absorption. The intervening absorber is inferred to have an X-ray column of ∿1022 cm-2. This is the first time that an absorption-line system has been identified with an X-ray absorber in a radio-quiet object.FJC thanks the DGES for partial financial support, under project PB95-0122.Peer Reviewe

Infrared identification of hard X-ray sources in the Galaxy

The nature of the low- to intermediate-luminosity (LX ∼ 1032–34 erg s−1) source population revealed in hard band (2–10 keV) X-ray surveys of the Galactic plane is poorly understood. To overcome such problem, we cross-correlated the XMM–Newton 3XMM-DR4 survey with the infrared Two Micron All Sky Survey and Galactic Legacy Infrared Mid-Plane Survey Extraordinaire catalogues. We identified reliable X-ray–infrared associations for 690 sources. We selected 173 sources having hard X-ray spectra, typical of hard X-ray high-mass stars (kT > 5 keV), and 517 sources having soft X-ray spectra, typical of active coronae. About 18 per cent of the soft sources are classified in the literature: ∼91 per cent as stars, with a minor fraction of Wolf–Rayet (WR) stars. Roughly 15 per cent of the hard sources are classified in the literature: ∼68 per cent as high-mass X-ray stars single or in binary systems (WR, Be and high-mass X-ray binaries – HMXBs), with a small fraction of G and B stars. We carried out infrared spectroscopic pilot observations at the William Herschel Telescope for five hard X-ray sources. Three of them are high-mass stars with spectral types WN7-8h, Ofpe/WN9 and Be, and LX ∼ 1032–1033erg s−1. One source is a colliding-wind binary, while another source is a colliding-wind binary or a supergiant fast X-ray transient in quiescence. The Be star is a likely γ-Cas system. The nature of the other two X-ray sources is uncertain. The distribution of hard X-ray sources in the parameter space made of X-ray hardness ratio, infrared colours and X-ray-to-infrared flux ratio suggests that many of the unidentified sources are new γ-Cas analogues, WRs and low LX HMXBs. However, the nature of the X-ray population with Ks ≥ 11 and average X-ray-to-infrared flux ratio remains unconstrained.We acknowledge financial support from the ARCHES project (7th Framework of the European Union, no. 313146). FJC acknowledges financial support from the Spanish Ministerio de Economía y Competitividad under project AYA2012-31447.Peer Reviewe

Exploring XMM-ATLAS with the ARCHES tools

Trabajo presentado al ARCHES Scientific Workshop: X-ray surveys with advanced multi-wavelength cross-identification methods, celebrado en Paris del 30 de noviembre al 2 de diciembre de 2015.Peer Reviewe

An excess of star-forming galaxies in the fields of high-redshift QSOs

We present submillimetre (submm) and mid-infrared (MIR) imaging observations of five fields centred on quasi-stellar objects (QSOs) at 1.7 <z< 2.8. All five QSOs were detected previously at submm wavelengths. At 850 (450) μm, we detect 17 (11) submillimetre galaxies (SMGs) in addition to the QSOs. The total area mapped at 850 μm is ∼28 arcmin2 down to rms noise levels of 1–2 mJy beam−1, depending on the field. Integral number counts are computed from the 850-μm data using the same analytical techniques adopted by ‘blank-field’ submm surveys. We find that the ‘QSO-field’ counts show a clear excess over the blank-field counts at deboosted flux densities of ∼2–4 mJy; at higher flux densities, the counts are consistent with the blank-field counts. Robust MIR counterparts are identified for all four submm detected QSOs and ∼60 per cent of the SMGs. The MIR colours of the QSOs are similar to those of the local ultraluminous infrared galaxy (ULIRG)/active galactic nuclei (AGN) Mrk 231 if placed at 1 <z< 3 whilst most of the SMGs have colours very similar to those of the local ULIRG Arp 220 at 1 <z< 3. MIR diagnostics therefore find no strong evidence that the SMGs host buried AGN although we cannot rule out such a possibility. Taken together our results suggest that the QSOs sit in regions of the early universe which are undergoing an enhanced level of major star formation activity, and should evolve to become similarly dense regions containing massive galaxies at the present epoch. Finally, we find evidence that the level of star formation activity in individual galaxies appears to be lower around the QSOs than it is around more powerful radio-loud AGN at higher redshifts.We thank Ian Smail for extensive comments on the draft manuscript and Mark Thompson for useful discussions. The JCMT is operated by The Joint Astronomy Centre on behalf of the Science and Technology Facilities Council of the United Kingdom, the Netherlands Organisation for Scientific Research and the National Research Council of Canada. JCMT data were taken under project IDs M03AU46, M03BU32 and M04BU14. This work is based (in part) on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech. JAS, MJP and FJC acknowledge support from the Royal Society. FJC acknowledges further support from the Spanish Ministerio de Educación y Ciencia under project ESP2006-13608

Metáforas tecnocientíficas en el discurso mediático: análisis hermenéutico e impacto socio-educativo

A concern with language usage and interpretation has been apparent throughout the history of the Spanish Language. Numerous semantic studies are available focusing on a variety of languages. Taking a study of Lakoff and Johnson’s Metaphors We Live By as our starting point, we can see how interpretations of certain metaphors commonly used in the English language can also be interpreted in Spanish. Thus, we have selected some examples from twenty-two opinion pieces, published in the Spanish press in 2012 and have observed the diversity of interpretations based on the writer’s creativity and intentionality.A lo largo de la historia de la lengua española, se ha hecho patente la preocupación por los usos lingüisticos y por su interpretación. Son muchos los numerosos estudios semánticos de los que disponemos, enfocados desde distintas lenguas. Partiendo del estudio de Lakoff y Johnson Metáforas de la vida cotidiana, podemos observar que las interpretaciones de algunas metáforas que se utilizan frecuentemente en lengua inglesa pueden ser interpretadas de igual manera en la lengua española. Para ello, hemos seleccionado algunos ejemplos de veintidós artículos de opinión, publicados en prensa escrita en España en el año 2012 y hemos observado que la diversidad de interpretaciones está basada en la creatividad y en la intencionalidad del hablante