Search

Your search keyword '"M G Haehnelt"' showing total 6 results
Start Over Author "M G Haehnelt"
6 results on '"M G Haehnelt"'

2. XQR-30: the ultimate XSHOOTER quasar sample at the reionization epoch

Author

Valentina D’Odorico, E Bañados, G D Becker, M Bischetti, S E I Bosman, G Cupani, R Davies, E P Farina, A Ferrara, C Feruglio, C Mazzucchelli, E Ryan-Weber, J-T Schindler, A Sodini, B P Venemans, F Walter, H Chen, S Lai, Y Zhu, F Bian, S Campo, S Carniani, S Cristiani, F Davies, R Decarli, A Drake, A-C Eilers, X Fan, P Gaikwad, S Gallerani, B Greig, M G Haehnelt, J Hennawi, L Keating, G Kulkarni, A Mesinger, R A Meyer, M Neeleman, M Onoue, A Pallottini, Y Qin, S Rojas-Ruiz, S Satyavolu, A Sebastian, R Tripodi, F Wang, M Wolfson, J Yang, M V Zanchettin, D'Odorico, Valentina, Bañados, E., Becker, G. D., Bischetti, M., Bosman, S. E. I., Cupani, G., Davies, R., Farina, E. P., Ferrara, Andrea, Feruglio, C., Mazzucchelli, C., Ryan-Weber, E., Schindler, J. -T., Sodini, A., Venemans, B. P., Walter, F., Chen, H., Lai, S., Zhu, Y., Bian, F., Campo, S., Carniani, Stefano, Cristiani, S., Decarli, R., Davies, F., Drake, A., Eilers, A. -C., Fan, X., Gaikwad, P., Gallerani, Simona, Greig, B., Haehnelt, M. G., Hennawi, J., Keating, L., Kulkarni, G., Mesinger, Andrei Albert, Meyer, R. A., Neeleman, M., Onoue, M., Pallottini, Andrea, Qin, Y., Rojas-Ruiz, S., Satyavolu, S., Sebastian, A., Tripodi, R., Wang, F., Wolfson, M., Yang, J., and Zanchettin, M. V.

Subjects
absorption line [quasars], dark age, Cosmology and Nongalactic Astrophysics (astro-ph.CO), first stars, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, emission line [quasars], Settore FIS/05 - Astronomia e Astrofisica, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), reionization, intergalactic medium, high-redshift [galaxies], Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The final phase of the reionization process can be probed by rest-frame UV absorption spectra of quasars at z>6, shedding light on the properties of the diffuse intergalactic medium within the first Gyr of the Universe. The ESO Large Programme "XQR-30: the ultimate XSHOOTER legacy survey of quasars at z~5.8-6.6" dedicated ~250 hours of observations at the VLT to create a homogeneous and high-quality sample of spectra of 30 luminous quasars at z~6, covering the rest wavelength range from the Lyman limit to beyond the MgII emission. Twelve quasar spectra of similar quality from the XSHOOTER archive were added to form the enlarged XQR-30 sample, corresponding to a total of ~350 hours of on-source exposure time. The median effective resolving power of the 42 spectra is R~11400 and 9800 in the VIS and NIR arm, respectively. The signal-to-noise ratio per 10 km/s pixel ranges from ~11 to 114 at $\lambda \simeq 1285$ \AA rest frame, with a median value of ~29. We describe the observations, data reduction and analysis of the spectra, together with some first results based on the E-XQR-30 sample. New photometry in the H and K bands are provided for the XQR-30 quasars, together with composite spectra whose characteristics reflect the large absolute magnitudes of the sample. The composite and the reduced spectra are released to the community through a public repository, and will enable a range of studies addressing outstanding questions regarding the first Gyr of the Universe., Comment: 21 pages, 10 figures. Final version accepted by MNRAS

Published
2023
Full Text
View/download PDF

6. The effect of (strong) discrete absorption systems on the Lyman α forest flux power spectrum.

Author

M. Viel, A., M. G. Haehnelt, A., R. F. Carswell, A., and T.-S. Kim, A.

Subjects
*SPECTRUM analysis, *ABSORPTION spectra, *QUASARS, *MOLECULAR spectroscopy, *DENSITY, *INTERSTELLAR medium
Abstract

We demonstrate that the Lyman α forest flux power spectrum of ‘randomized’ quasi-stellar object (QSO) absorption spectra is comparable in shape and amplitude to the flux power spectrum of the original observed spectra. In the randomized spectra a random shift in wavelength has been added to the observed absorption lines as identified and fitted with vpfit. At the ‘3D’ power spectrum of the randomized flux agrees with that of observed spectra within the errors. At larger scales it still approaches 50 per cent of that of the observed spectra. At smaller scales the flux power spectrum is dominated by metal lines. Lines of increasing column density contribute to the ‘3D’ flux power spectrum at increasingly larger scales. Lines with dominate at the peak of the ‘3D’ power spectrum while strong absorbers with contribute at large scales, . We further show that a fraction of ≳15 per cent of the mean flux decrement is contributed by strong absorbers at . Analysis of the flux power spectrum which use numerical simulations with too few strong absorption systems calibrated with the observed mean flux may underestimate the inferred rms fluctuation amplitude and the slope of the initial dark matter power spectrum. [ABSTRACT FROM AUTHOR]

Published
2004
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results