89 research outputs found
A framework to measure the properties of intergalactic metal systems with two-point flux statistics
The abundance, temperature, and clustering of metals in the intergalactic
medium are important parameters for understanding their cosmic evolution and
quantifying their impact on cosmological analysis with the Ly forest.
The properties of these systems are typically measured from individual quasar
spectra redward of the quasar's Ly emission line, yet that approach
may provide biased results due to selection effects. We present an alternative
approach to measure these properties in an unbiased manner with the two-point
statistics commonly employed to quantify large-scale structure. Our model
treats the observed flux of a large sample of quasar spectra as a continuous
field and describes the one-dimensional, two-point statistics of this field
with three parameters per ion: the abundance (column density distribution),
temperature (Doppler parameter) and clustering (cloud-cloud correlation
function). We demonstrate this approach on multiple ions (e.g., C IV, Si IV, Mg
II) with early data from the Dark Energy Spectroscopic Instrument (DESI) and
high-resolution spectra from the literature. Our initial results show some
evidence that the C IV abundance is higher than previous measurements and
evidence for abundance evolution over time. The first full year of DESI
observations will have over an order of magnitude more quasar spectra than this
study. In a future paper we will use those data to measure the growth of
clustering and its impact on the Ly forest, as well as test other DESI
analysis infrastructure such as the pipeline noise estimates and the resolution
matrix.Comment: 15 pages, 14 figure
Ultrastructural features of Mimulus aurantiacus (Scrophulariaceae) pollen tubes in vivo
Determination of the optimal matching position for setup images and minimal setup margins in adjuvant radiotherapy of breast and lymph nodes treated in voluntary deep inhalation breath-hold
The Effects of Zinc Treatment on the Blood–Brain Barrier Permeability and Brain Element Levels During Convulsions
Bleomycin-induced in vitro 3D spheroid model to emulate pulmonary fibrosis
[No Abstract Available]Ege University Scientific Research Fund (Grant number: FGA-2020-21686) and Presidency of the Republic of Turkey, Presidency of Strategy and Budget (Grant number: 2019K12-149080) are appreciated for their supports.Ege University Scientific Research Fund [FGA-2020-21686]; Presidency of the Republic of Turkey, Presidency of Strategy and Budget [2019K12-149080
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