Dating individual quasars with the He ii proximity effect
نویسندگان
چکیده
منابع مشابه
Combining U–Th/He eruption age dating and He cosmogenic dating to constrain landscape evolution
Earth analogues for Martian canyons. Steep-walled, amphitheater canyons on Mars have been invoked as evidence for underground water flow because of their similarities to seepage or sapping valleys/canyons on Earth. However, seepage canyon formation on Earth is speculative, particularly in basalt terrains (Lamb et al., 2006), and therefore analogies to Mars may be inappropriate. One of these Ear...
متن کاملKey words: Quasars: absorption lines – Quasars: individual: HE 1122−1649, HE 0515−4414 Galaxies: abundances – Galaxies: evolution – Galaxies: ISM – Cosmology: observations
Detailed analysis of the spectral lines from two low redshift damped Lyman alpha absorbers (DLA) confirms that they are a heterogeneous population. Both systems have low metal abundances of approximately 0.05 to 0.1 solar. The abundance pattern of the DLA at z = 1.15 towards HE 0515-4414 shows dust depletion comparable to that found in our Galaxy, while the system at z = 0.68 towards HE 1122-16...
متن کاملPhoto-heating and the fate of hard photons during the reionisation of He II by quasars
We use a combination of analytic and numerical arguments to consider the impact of quasar photo-heating during He II reionisation on the thermal evolution of the intergalactic medium (IGM). We demonstrate that rapid (∆z < 0.1–0.2), strong (∆T > 10 K) photo-heating is difficult to achieve across the entire IGM unless quasar spectra are significantly harder than implied by current observational c...
متن کاملQuasars near the line of sight towards Q 0302 − 003 and the transverse proximity effect ⋆
We report the discovery of the faint (V ≃ 21.7) quasar QSO 03027−0010 at z = 2.808 in the vicinity of Q 0302−003, one of the few quasars observed with STIS to study intergalactic He absorption. Together with another newly discovered QSO at z = 2.29, there are now 6 QSOs known near the line of sight towards Q 0302−003, of which 4 are located within the redshift region 2.76 < ∼ z < ∼ 3.28 cove...
متن کاملStatistical Detection of the He ii Transverse Proximity Effect: Evidence for Sustained Quasar Activity for >25 Million Years
Citation: Schmidt TM, Worseck G, Hennawi JF, Prochaska JX, Crighton NHM, Lukić Z and Oñorbe J (2017) Statistical Detection of the He II Transverse Proximity Effect: Evidence for Sustained Quasar Activity for >25 Million Years. Front. Astron. Space Sci. 4:23. doi: 10.3389/fspas.2017.00023 Statistical Detection of the He II Transverse Proximity Effect: Evidence for Sustained Quasar Activity for >...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 2021
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/stab1685