| Autor: |
de Beer, S, Cantalupo, S, Travascio, A, Pezzulli, G, Galbiati, M, Fossati, M, Fumagalli, M, Lazeyras, T, Pensabene, A, Theuns, T, Wang, W |
| Předmět: |
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| Zdroj: |
Monthly Notices of the Royal Astronomical Society; Dec2023, Vol. 526 Issue 2, p1850-1873, 24p |
| Abstrakt: |
Ly α nebulae ubiquitously found around z > 2 quasars can supply unique constraints on the properties of the circumgalactic medium, such as its density distribution, provided the quasar halo mass is known. We present a new method to constrain quasar halo masses based on the line-of-sight velocity dispersion maps of Ly α nebulae. By using MUSE-like mock observations obtained from cosmological hydrodynamic simulations under the assumption of maximal quasar fluorescence, we show that the velocity dispersion radial profiles of Ly α emitting gas are strongly determined by gravity and that they are thus self-similar with respect to halo mass when rescaled by the virial radius. Through simple analytical arguments and by exploiting the kinematics of He ii 1640 Å emission for a set of observed nebulae, we show that Ly α radiative transfer effects plausibly do not change the shape of the velocity dispersion profiles but only their normalization without breaking their self-similarity. Taking advantage of these results, we define the variable |$\eta ^{140-200}_{40-100}$| as the ratio of the median velocity dispersion in two specifically selected annuli and derive an analytical relation between |$\eta ^{140-200}_{40-100}$| and the halo mass which can be directly applied to observations. We apply our method to 37 observed quasar Ly α nebulae at 3 < z < 4.7 and find that their associated quasars are typically hosted by ∼1012.16 ± 0.14M⊙ haloes independent of redshift within the explored range. This measurement, which is completely independent of clustering methods, is consistent with the lowest mass estimates based on quasar autocorrelation clustering at z∼3 and with quasar-galaxies cross-correlation results. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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