Examinando por Autor "Andrews, Moira"

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    Ítem
    Anisotropic correlation functions as tracers of central galaxy alignments in simulations
    (Oxford University Press, 2023-06) Rodriguez, Facundo; Merchán, Manuel; Artale, M. Celeste; Andrews, Moira
    Motivated by observational results, we use IllustrisTNG hydrodynamical numerical simulations to study the alignment of the central galaxies in groups with the surrounding structures. This approach allows us to analyse galaxy and group properties not available in observations. To perform this analysis, we use a modified version of the two-point cross-correlation function and a measure of the angle between the semimajor axes of the central galaxies and the larger structures. Overall, our results reproduce observational ones, as we find large-scale anisotropy, which is dominated by the red central galaxies. In addition, the latter is noticeably more aligned with their group than the blue ones. In contrast to the observations, we find a strong dependence of the anisotropy on the central galaxy with mass, probably associated with the inability of observational methods to determine them. This result allows us to link the alignment to the process of halo assembly and the well-known dependence of halo anisotropy on mass. When we include the dark matter distribution in our analysis, we conclude that the galaxy alignment found in simulations (and observations) can be explained by a combination of physical processes at different scales: the central galaxy aligns with the dark matter halo it inhabits, and this, in turn, aligns with the surrounding structures at large scales.
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    The One-hundred-deg2 DECam Imaging in Narrowbands (ODIN): Survey Design and Science Goals
    (Institute of Physics, 2024-02-11) Lee, Kyoung-Soo; Gawiser, Eric; Park, Changbom; Yang, Yujin; Valdes, Francisco; Lang, Dustin; Ramakrishnan, Vandana; Moon, Byeongha; Firestone, Nicole; Appleby, Stephen; Artale, Maria Celeste; Andrews, Moira; Bauer, Franz; Benda, Barbara; Broussard, Adam; Chiang, Yi-Kuan; Ciardullo, Robin; Dey, Arjun; Farooq, Rameen; Gronwall, Caryl; Guaita, Lucia; Huang, Yun; Hwang, Ho Seong; Sang Hyeok; Jeong, Woong-Seob; Karthikeyan, Shreya; Kim, Hwihyun; Kim, Seongjae; Kumar, Ankit; Nagaraj, Gautam R.; Nantais, Julie; Padilla, Nelson; Park, Jaehong; Pope, Alexandra; Popescu, Roxana; Schlegel, David; Seo, Eunsuk; Singh, Akriti; Song, Hyunmi; Troncoso, Paulina; Vivas, A. Katherina; Zabludoff, Ann; Zenteno, Alfredo
    We describe the survey design and science goals for One-hundred-deg2 DECam Imaging in Narrowbands (ODIN), a NOIRLab survey using the Dark Energy Camera (DECam) to obtain deep (AB ∼ 25.7) narrowband images over an unprecedented area of sky. The three custom-built narrowband filters, N419, N501, and N673, have central wavelengths of 419, 501, and 673 nm and respective FWHM of 7.5, 7.6, and 10.0 nm, corresponding to Lyα at z = 2.4, 3.1, and 4.5 and cosmic times of 2.8, 2.1, and 1.4 Gyr, respectively. When combined with even deeper, public broadband data from the Hyper Suprime-Cam, DECam, and in the future, the Legacy Survey of Space and Time, the ODIN narrowband images will enable the selection of over 100,000 Lyα-emitting (LAE) galaxies at these epochs. ODIN-selected LAEs will identify protoclusters as galaxy overdensities, and the deep narrowband images enable detection of highly extended Lyα blobs (LABs). Primary science goals include measuring the clustering strength and dark matter halo connection of LAEs, LABs, and protoclusters, and their respective relationship to filaments in the cosmic web. The three epochs allow for the redshift evolution of these properties to be determined during the period known as Cosmic Noon, where star formation was at its peak. The narrowband filter wavelengths are designed to enable interloper rejection and further scientific studies by revealing [O ii] and [O iii] at z = 0.34, Lyα and He ii 1640 at z = 3.1, and Lyman continuum plus Lyα at z = 4.5. Ancillary science includes similar studies of the lower-redshift emission-line galaxy samples and investigations of nearby star-forming galaxies resolved into numerous [O iii] and [S ii] emitting regions.