Zobrazeno 1 - 10
of 78
pro vyhledávání: '"Crighton, Neil H. M."'
Autor:
Robert, P. Frédéric, Murphy, Michael T., O'Meara, John M., Crighton, Neil H. M., Fumagalli, Michele
We report the discovery of three new "near-pristine" Lyman Limit Systems (LLSs), with metallicities ~1/1000 solar, at redshifts 2.6, 3.8 and 4.0, with a targeted survey at the Keck Observatory. High resolution echelle spectra of eight candidates yiel
Externí odkaz:
http://arxiv.org/abs/2206.02947
Autor:
Robert, P. Frédéric, Murphy, Michael T., O'Meara, John M., Crighton, Neil H. M., Fumagalli, Michele
We report the discovery and analysis of only the third Lyman-limit system in which a high-quality resolution, echelle spectrum reveals no metal absorption lines, implying a metallicity $\lesssim$1/10000 solar. Our HIRES spectrum of the background qua
Externí odkaz:
http://arxiv.org/abs/1812.05098
Autor:
Crighton, Neil H. M., Prochaska, J. Xavier, Murphy, Michael T., O'Meara, John M., Worseck, Gabor, Smith, Britton D.
Lyman Limit systems (LLSs) trace the low-density circumgalactic medium and the most dense regions of the intergalactic medium, so their number density and evolution at high redshift, just after reionisation, are important to constrain. We present a s
Externí odkaz:
http://arxiv.org/abs/1810.10040
Autor:
Codoreanu, Alex, Ryan-Weber, Emma V., García, Luz Ángela, Crighton, Neil H. M., Becker, George, Pettini, Max, Madau, Piero, Venemans, Bram
We present further results of a survey for absorption line systems in the spectra of four high redshift quasars (5.79 $\le$ z$_{\textrm{em}}$ $\le$ 6.13) obtained with the ESO Very Large Telescope X-Shooter. We identify 36 $\textrm{CIV}$ and 7 $\text
Externí odkaz:
http://arxiv.org/abs/1809.05813
Autor:
Rubin, Kate H. R., Diamond-Stanic, Aleksandar M., Coil, Alison L., Crighton, Neil H. M., Stewart, Kyle R.
The circumgalactic medium (CGM) close to ~L* star-forming galaxies hosts strong MgII 2796 absorption (with equivalent width W_2796>0.1 Ang) with a near-unity covering fraction. To characterize the spatial coherence of this absorption, we analyze the
Externí odkaz:
http://arxiv.org/abs/1806.08801
Autor:
Rubin, Kate H. R., Diamond-Stanic, Aleksandar M., Coil, Alison L., Crighton, Neil H. M., Moustakas, John
Spectroscopy of background QSO sightlines passing close to foreground galaxies is a potent technique for studying the circumgalactic medium (CGM). QSOs are effectively point sources, however, limiting their potential to constrain the size of circumga
Externí odkaz:
http://arxiv.org/abs/1711.08807
Autor:
Codoreanu, Alex, Ryan-Weber, Emma V., Crighton, Neil H. M., Becker, George, Pettini, Max, Madau, Piero, Venemans, Bram
Publikováno v:
Monthly Notices of the Royal Astronomical Society, 472 1, 2017, 1023 - 1051
We present the results of a survey for intervening MgII absorbers in the redshift range z $\simeq$2-6 in the foreground of four high redshift quasar spectra, 5.79$\le z_{em}\le$6.133, obtained with the ESO VLT X-shooter. We identify 24 absorbers at $
Externí odkaz:
http://arxiv.org/abs/1708.00304
Autor:
Schmidt, Tobias M., Worseck, Gabor, Hennawi, Joseph F., Prochaska, J. Xavier, Crighton, Neil H. M.
The HeII transverse proximity effect -- enhanced HeII Ly$\alpha$~transmission in a background sightline caused by the ionizing radiation of a foreground quasar -- offers a unique opportunity to probe the morphology of quasar-driven HeII reionization.
Externí odkaz:
http://arxiv.org/abs/1701.08769
Autor:
Finn, Charles W., Morris, Simon L., Tejos, Nicolas, Crighton, Neil H. M., Perry, Robert, Fumagalli, Michele, Bielby, Rich, Theuns, Tom, Schaye, Joop, Shanks, Tom, Liske, Jochen, Gunawardhana, Madusha L. P., Bartle, Stephanie
We present new results on the auto- and cross-correlation functions of galaxies and OVI absorbers in a $\sim 18~\textrm{Gpc}^3$ comoving volume at $z < 1$. We use a sample of 51,296 galaxies and 140 OVI absorbers in the column density range $13 \less
Externí odkaz:
http://arxiv.org/abs/1604.02150
The first stars, known as Population III (PopIII), produced the first heavy elements, thereby enriching their surrounding pristine gas. Previous detections of metals in intergalactic gas clouds, however, find a heavy element enrichment larger than $1
Externí odkaz:
http://arxiv.org/abs/1512.00477