The 2dF-SDSS LRG and QSO Survey: the QSO luminosity function at 0.4 < z < 2.6

By Scott M. Croom, Gordon Richards, T. Shanks, B. Boyle, M. Strauss, Adam D. Myers, Robert Nichol, Kevin A. Pimbblet, N. Ross, D. Schneider and 11 more. 2009

188 citations recorded by the source corpus.

We present the quasi-stellar object (QSO) luminosity function (LF) of the completed 2dF–SDSS LRG and QSO (2SLAQ) survey, based on QSOs photometrically selected from Sloan Digital Sky Survey (SDSS) imaging data and then observed spectroscopically using the 2dF instrument on the Anglo-Australian Telescope. We analyse 10 637 QSOs in the redshift range 0.4 20.0, as found previously by Richards et al. The LF is consistent with other previous, much smaller, samples produced to the depth of 2SLAQ. By combining the 2SLAQ and SDSS QSO samples, we produce a QSO LF with an unprecedented combination of precision and dynamic range. With this we are able to accurately constrain both the bright and faint ends of the QSO LF. While the overall trends seen in the evolution of the QSO LF appear similar to pure luminosity evolution, the data show very significant departures from such a model. Most notably we see clear evidence that the number density of faint QSOs peaks at lower redshift than bright QSOs: QSOs with Mg > −23 have space densities which peak at z 2. By fitting simple LF models in narrow Mg intervals, we find that this downsizing is significant at the 99.98 per cent level. We show that LF models which follow the pure luminosity evolution form [i.e. M ∗ ≡ M ∗(z)], but with a redshift-dependent bright-end slope and an additional density evolution term, � ∗ ≡ � ∗ (z), provide a much improved fit to the data. The bright-end slope, α, steepens from α �− 3.0 at z � 0.5 to α =− 3.5 at z � 2.5. This steepening is significant at the 99.9 per cent level. We find a decline in � ∗ from z � 0.5 to 2.5 which is significant at the

Subfields: Astronomy and Astrophysics

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Citations in the corpus

What drives the growth of black holes (2011, background): “…for optically selected and radio selected AGNs (e.g., Richards et al., 2005; Bongiorno et al., 2007; Hopkins et al., 2007; Rigby et al., 2008, 2011; Croom et al., 2009; Smolčić et al., 2009).7 Obscured AGNs are found to trace the same evolution as unobscured AGNs of the same lu- 7Analogous…”
Accretion-driven evolution of black holes: Eddington ratios, duty cycles and active galaxy fractions (2011, background): “The accretion onto the very massive black holes with log MBH/M⊙ > 8 always peaks at z ∼ 2, concurrent with the peak in the emissivity of luminous optical quasars (e.g., Osmer 1982; Richards et al. 2006; Croom et al. 2009).”
Evolution of the AGN UV luminosity function from redshift 7.5 (2018, methodology): “MNRAS 000, 1–30 (2018) catalogue (Schneider et al. 2010) and the 2SLAQ survey catalogue (Croom et al. 2009a).”
THE z = 5 QUASAR LUMINOSITY FUNCTION FROM SDSS STRIPE 82 (2012, methodology): “3 quasars typically find α = −1.5 (Hunt et al. 2004; Richards et al. 2005; Siana et al. 2008; Croom et al. 2009), while observations at high redshift favor a steeper value of α = −1.7 (Glikman et al. 2010; Ikeda et al. 2011; Masters et al. 2012), albeit with large uncertainties due to the…”
The Sydney-AAO Multi-object Integral field spectrograph (2011, background): “This is most clearly seen in evolution of luminous quasars from z = 0 to z ≃ 6 (Richards et al. 2006; Croom et al. 2009), which have a strong peak in space density at z ≃ 2 − 3.”
The bolometric quasar luminosity function at z = 0–7 (2020, methodology): “Outside the Kulkarni et al. (2018) compilation, we include measurements from Fontanot et al. (2007); Croom et al. (2009); Shen & Kelly (2012); Jiang et al. (2016); Palanque-Delabrouille et al. (2016); Yang et al. (2016); Akiyama et al. (2018); Matsuoka et al. (2018); McGreer et al. (2018); Wang et…”
MODELING THE TIME VARIABILITY OF SDSS STRIPE 82 QUASARS AS A DAMPED RANDOM WALK (2010, background): “At a given redshift, a simulated value for absolute magnitude can be readily drawn from an adopted luminosity function (e.g., Croom et al. 2009 and references therein).”
THE CANADA–FRANCE HIGH-z QUASAR SURVEY: NINE NEW QUASARS AND THE LUMINOSITY FUNCTION AT REDSHIFT 6 (2009, methodology): “The break magnitude and β found by Croom et al. (2009) are plotted in Figure 6 (we converted from Mg(z = 2) to M1450 using the relation in Croom et al. and adapted for our cosmology).”
Grand unification of AGN activity in the ΛCDM cosmology (2009, methodology): “4 < z < 0.68 estimated from the 2dF (Croom et al. 2004) and 2dF-SDSS QSO survey (Croom et al. 2009).”
The bright end of the galaxy luminosity function at z≃7: before the onset of mass quenching? (2013, background): “Lower redshift z < 3 results tend to favour α = −1.5 (Croom et al. 2009), with a tenuous steepening observed with α ' −1.7 to higher redshifts (Masters et al. 2012).”
COSMIC REIONIZATION AFTER PLANCK: COULD QUASARS DO IT ALL? (2015, methodology): “In the redshift range 0.68 < z < 3.0, the g-band LF of Palanque-Delabrouille et al. (2013) combines SDSS-III and Multiple Mirror Telescope quasar data with the 2SLAQ sample of Croom et al. (2009).”
The quasar relation through cosmic time – II. Evidence for evolution from z = 3 to the present age (2009, background): “In particular: i- the evolution of the quasar luminosity function (Dunlop & Peacock 1990; Fontanot et al. 2007; Croom et al. 2009) closely matches the trend of the star formation density through Cosmic ages (Madau Pozzetti & Dickinson 1998); ii- massive black holes are found in virtually all…”
THE FINAL SDSS HIGH-REDSHIFT QUASAR SAMPLE OF 52 QUASARS AT z > 5.7 (2016, background): “At low redshift ( z 3), the QLF has a very steep bright-end slope b -3 and a much flatter faint-end slope a ~ -1.5 (e.g., Richards et al. 2006; Croom et al. 2009; Ross et al. 2013).”
The Coevolution of Galaxies and Supermassive Black Holes: Insights from Surveys of the Contemporary Universe (2014, methodology): “The QSO luminosity function of the completed 2dF-SDSS opticallyselected QSO survey (Croom et al. 2009) agrees extremely well in both amplitude and shape with the X-ray selected QSO luminosity functions of Hasinger et al. (2005).”
THE SDSS-III BARYON OSCILLATION SPECTROSCOPIC SURVEY: THE QUASAR LUMINOSITY FUNCTION FROM DATA RELEASE NINE (2012, methodology): “…the deep X-ray studies (Miyaji et al. 2001; Ueda et al. 2003; Hasinger et al. 2005), and then in the optical by the 2SLAQ QSO survey (Richards et al. 2005; Croom et al. 2009a) see the trend for “AGN Downsizing”, with the number density of fainter AGN peaking at lower-redshift than the luminous AGN.”
The VISTA deep extragalactic observations (VIDEO) survey (2012, background): “…important to note that the epoch over which VIDEO is aimed is a crucial one in the history of the Universe, as this is when the bulk of the star formation (e.g. Madau et al. 1996; Hopkins & Beacom 2006; Lapi et al. 2011) and accretion (e.g. Ueda et al. 2003; Croom et al. 2009) activity took place.”
GALAXY ZOO: THE FUNDAMENTALLY DIFFERENT CO-EVOLUTION OF SUPERMASSIVE BLACK HOLES AND THEIR EARLY- AND LATE-TYPE HOST GALAXIES (2010, background): “…active galactic nuclei (AGN) in deep fields observed by Chandra and XMM-Newton have revealed that the most luminous AGN were most common in the early Universe, while the lower-luminosity AGN peak later (Ueda et al. 2003; Merloni 2004; Barger et al. 2005; La Franca et al. 2005; Croom et al. 2009).”
Cosmic X-ray surveys of distant active galaxies (2015, background): “The downsizing behavior of AGNs has also now been found in optically selected (e.g., Bongiorno et al 2007; Croom et al 2009; Shen and Kelly 2012; Ross et al 2013) and radio-selected (e.g., Massardi et al 2010; Rigby et al 2011) samples, confirming the generality of this phenomenon, although X-ray…”