arXiv subjects

Lana Eid

Publications and source records attributed to Lana Eid.

3 recordsLinked to original sources

arXiv2025

Source REconstruction of Arcs behind Cluster Halos (SourceREACH): A New Source Reconstruction Algorithm Optimized for Giant Arcs and Galaxy Cluster Lenses

We introduce a new algorithm designed for use with extended lensed images, specifically giant arcs lensed by galaxy clusters. These highly magnified images contain important information about both the mass distribution of the cluster and the properties of the background source, but modeling them requires significant computational effort. Our new source reconstruction methodology is designed to be accurate and efficient for high-resolution observations in which point spread function effects are not significant. The overall process deconvolves the observed image by the point spread function, de-lenses the image pixels, and uses interpolation or regression with smoothing to determine the model source. By working with de-lensed points, the method accounts for varying resolution across the source plane. We evaluate the speed and accuracy of different interpolation and regression methods using both mock data and real data for the giant arc in Abell 370. We find that utilizing K Nearest Neighbor Regression results in the best balance of noise smoothing and preservation of compact detail in the source.

astro-ph.CO↗

arXiv2025

Constraints from the Giant Arc in Abell 370. A New Framework for Understanding Systematic Errors in Cluster Lens Modeling. IV. Constraints from the Giant Arc in Abell 370

We aim to improve cluster lens modeling and source reconstruction by utilizing the full information in giant, caustic-crossing arcs lensed by galaxy clusters. Lens models are generally constrained using image positions and assuming point sources, but spatially extended giant arcs provide more constraints; however, they require a more complex model that accounts for the structure of the extended source. We seek to determine whether improvements to the lens model and reconstructed source merit the difficulty of handling the extra constraints. We choose the spatially extended $z=0.725$ giant arc in the $z=0.375$ Abell 370 galaxy cluster field for our study. We present 1) a series of pixel-based source reconstructions for cluster mass models exploring the range of uncertainties in our fiducial model, 2) a similar analysis done using a prototype \textit{python} de-lensing code for cluster mass models from each of the Hubble Frontier Fields modeling teams, 3) an optimized model with pixel-based source reconstructions, and 4) and an investigation of how our optimized model affects the cluster mass model locally and globally in the highest-magnification regions. We find that our optimized model 1) is able to correct resolution-limited assumptions in cluster model inputs local to the arc, 2) has significantly smaller arc model residuals than results from the standard Hubble Frontier Fields models, and 3) affects the critical curves and therefore the information derived from highest-magnification zones most significantly in regions local to the arc.

astro-ph.CO↗

arXiv2024

ODIN: Improved Narrowband Ly$α$ Emitter Selection Techniques for $z$ = 2.4, 3.1, and 4.5

Lyman-Alpha Emitting galaxies (LAEs) are typically young, low-mass, star-forming galaxies with little extinction from interstellar dust. Their low dust attenuation allows their Ly$α$ emission to shine brightly in spectroscopic and photometric observations, providing an observational window into the high-redshift universe. Narrowband surveys reveal large, uniform samples of LAEs at specific redshifts that probe large scale structure and the temporal evolution of galaxy properties. The One-hundred-deg$^2$ DECam Imaging in Narrowbands (ODIN) utilizes three custom-made narrowband filters on the Dark Energy Camera (DECam) to discover LAEs at three equally spaced periods in cosmological history. In this paper, we introduce the hybrid-weighted double-broadband continuum estimation technique, which yields improved estimation of Ly$α$ equivalent widths. Using this method, we discover 6032, 5691, and 4066 LAE candidates at $z =$ 2.4, 3.1, and 4.5 in the extended COSMOS field ($\sim$9 deg$^2$). We find that [O II] emitters are a minimal contaminant in our LAE samples, but that interloping Green Pea-like [O III] emitters are important for our redshift 4.5 sample. We introduce an innovative method for identifying [O II] and [O III] emitters via a combination of narrowband excess and galaxy colors, enabling their study as separate classes of objects. We present scaled median stacked SEDs for each galaxy sample, revealing the overall success of our selection methods. We also calculate rest-frame Ly$α$ equivalent widths for our LAE samples and find that the EW distributions are best fit by exponential functions with scale lengths of $w_0$ = 53 $\pm$ 1, 65 $\pm$ 1, and 59 $\pm$ 1 Angstroms, respectively.

astro-ph.GA↗