ORCID Profile
0000-0002-7248-1566
Current Organisation
York University
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: American Astronomical Society
Date: 03-11-2018
Abstract: Deep near-infrared photometric surveys are efficient in identifying high-redshift galaxies, however, they can be prone to systematic errors in photometric redshift. This is particularly salient when there is limited s ling of key spectral features of a galaxy’s spectral energy distribution (SED), such as for quiescent galaxies where the expected age-sensitive Balmer/4000 Å break enters the K -band at z 4. With single-filter s ling of this spectral feature, degeneracies between SED models and redshift emerge. A potential solution to this comes from splitting the K band into multiple filters. We use simulations to show an optimal solution is to add two medium-band filters, K blue ( λ cen = 2.06 μ m, Δ λ = 0.25 μ m) and K red ( λ cen = 2.31 μ m, Δ λ = 0.27 μ m), that are complementary to the existing K s filter. We test the impact of the K -band filters with simulated catalogs comprised of galaxies with varying ages and signal-to-noise. The results suggest that the K -band filters do improve photometric redshift constraints on z 4 quiescent galaxies, increasing precision and reducing outliers by up to 90%. We find that the impact from the K -band filters depends on the signal-to-noise, the redshift, and the SED of the galaxy. The filters we designed were built and used to conduct a pilot of the FLAMINGOS-2 Extragalactic Near-Infrared K -band Split survey. While no new z 4 quiescent galaxies are identified in the limited area pilot, the K blue and K red filters indicate strong Balmer/4000 Å breaks in existing candidates. Additionally, we identify galaxies with strong nebular emission lines, for which the K -band filters increase photometric redshift precision and in some cases indicate extreme star formation.
Publisher: American Astronomical Society
Date: 24-09-2014
Publisher: American Astronomical Society
Date: 12-03-2015
Publisher: American Astronomical Society
Date: 05-02-2020
Publisher: American Astronomical Society
Date: 23-03-2201
Publisher: American Astronomical Society
Date: 08-06-2017
Publisher: American Astronomical Society
Date: 02-2023
Abstract: We present a new rest-frame color–color selection method using synthetic u s − g s and g s − i s , ( ugi ) s colors to identify star-forming and quiescent galaxies. Our method is similar to the widely used U − V versus V − J ( UVJ ) diagram. However, UVJ suffers known systematics. Spectroscopic c aigns have shown that UVJ -selected quiescent s les at z ≳ 3 include ∼10%–30% contamination from galaxies with dust-obscured star formation and strong emission lines. Moreover, at z 3, UVJ colors are extrapolated because the rest-frame band shifts beyond the coverage of the deepest bandpasses at μ m (typically Spitzer/IRAC 4.5 μ m or future JWST/NIRCam observations). We demonstrate that ( ugi ) s offers improvements to UVJ at z 3, and can be applied to galaxies in the JWST era. We apply ( ugi ) s selection to galaxies at 0.5 z 6 from the (observed) 3D-HST and UltraVISTA catalogs, and to the (simulated) JAGUAR catalogs. We show that extrapolation can affect ( V − J ) 0 color by up to 1 mag, but changes ( g s − i s ) 0 color by ≤0.2 mag, even at z ≃ 6. While ( ugi ) s -selected quiescent s les are comparable to UVJ in completeness (both achieve ∼85%–90% at z = 3–3.5), ( ugi ) s reduces contamination in quiescent s les by nearly a factor of 2, from ≃35% to ≃17% at z = 3, and from ≃60% to ≃33% at z = 6. This leads to improvements in the true-to-false-positive ratio (TP/FP), where we find TP/FP ≳2.2 for ( ugi ) s at z ≃ 3.5 − 6, compared to TP/FP 1 for UVJ -selected s les. This indicates that contaminants will outnumber true quiescent galaxies in UVJ at these redshifts, while ( ugi ) s will provide higher-fidelity s les.
Publisher: Oxford University Press (OUP)
Date: 19-05-2016
No related grants have been discovered for Cemile Marsan.