English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We use the spectra of 22,000 nearby early-type galaxies from the SloanDigital Sky Survey (SDSS) to determine the age distribution of these galaxiesas a function of their velocity dispersion sigma_v in the range 100 km/s <sigma_v < 280 km/s. We then combine the inferred age-distributions with thelocal abundance of spheroids, including early-type galaxies and late-typebulges, to predict the evolution of the quasar luminosity function (LF) in theredshift range 0<z<6. We make the following simple assumptions: (i) theformation of stars in each galaxy, at the epoch identified with the meanmass-weighted stellar age, is accompanied by the prompt assembly of the nuclearsupermassive black hole (SMBH); (ii) the mass of the SMBH obeys theM_bh-sigma_v correlation observed in nearby galaxies; (iii) the SMBH radiatesat a fraction f_Edd of the Eddington limit for a fixed duration t_Q, and isidentified as a luminous quasar during this epoch, (iv) the intrinsicdispersions in the Eddington ratio and the M_bh-sigma_v relation produce acombined scatter of Delta(log L_Q) around the mean logarithmic quasarluminosity <log L_Q> at fixed sigma_v. These assumptions require that the SMBHremnants of quasars with bolometric luminosity below L_bol=10^{12.5} f_EddL_sun reside predominantly in bulges of late type galaxies. We find thatevolution of the observed quasar LF can be fit over the entire redshift rangein this simple model, 0<z<6 with the choices of Delta(log L_Q)=0.6-0.9, t_Q=(6-8)x10^7 yr, and <f_Edd>=0.3-0.5. We find no evidence that any of the modelparameters evolves with redshift, supporting the strong connection between theformation of stars and nuclear SMBHs in spheroids.Comment: Submitted to Ap

Reconstructing the Cosmic Evolution of Quasars from the Age Distribution of Local Early‐Type Galaxies