A highly elongated lens at z = 0.87

• Verfasst von: Zitrin, Adi [VerfasserIn]
• Titel: A highly elongated lens at z = 0.87
• Titelzusatz: first strong-lensing analysis of el Gordo
• Verf.angabe: Adi Zitrin, Felipe Menanteau, John P. Hughes, Dan Coe, L. Felipe Barrientos, Leopoldo Infante, and Rachel Mandelbaum
• E-Jahr: 2013
• Jahr: 2013 May 30
• Umfang: 6 S.
• Teil: volume:770
• Teil: year:2013
• Teil: number:1
• Teil: elocationid:L15
• Teil: pages:1-6
• Teil: extent:6
• Fussnoten: Gesehen am 02.08.2021
• Titel Quelle: Enthalten in: The astrophysical journal / 2
• Ort Quelle: London : Institute of Physics Publ., 1995
• Jahr Quelle: 2013
• Band/Heft Quelle: 770(2013), 1, Artikel-ID L15, Seite 1-6
• ISSN Quelle: 2041-8213
• DOI: doi:10.1088/2041-8205/770/1/L15
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1765222176

Abstract

We present the first strong-lensing (SL) analysis of the galaxy cluster ACT-CL J0102−4915 (El Gordo), in recent HST/ACS images, revealing a prominent strong lens at a redshift of z = 0.87. This finding adds to the already-established unique properties of El Gordo: it is the most massive, hot, X-ray luminous, and bright Sunyaev-Zeldovich effect cluster at z ≳ 0.6, and the only “bullet”-like merging cluster known at these redshifts. The lens consists of two merging massive clumps, where, for a source redshift of zs ∼ 2, each clump exhibits only a small, separate critical area, with a total area of 0.69 ± 0.11□′ over the two clumps. For a higher source redshift, zs ∼ 4, the critical curves of the two clumps merge together into one bigger and very elongated lens (axis ratio ≃ 5.5), enclosing an effective area of 1.44 ± 0.22□′. The critical curves continue expanding with increasing redshift so that for high-redshift sources (zs ≳ 9) they enclose an area of ∼1.91 ± 0.30□′ (effective θe ≃ 46.″8 ± 3.″7) and a mass of 6.09 ± 1.04 × 1014 M☉. According to our model, the area of high magnification (μ > 10) for such high-redshift sources is ≃1.2□′, and the area with μ > 5 is ≃2.3□′, making El Gordo a compelling target for studying the high-redshift universe. We obtain a strong lower limit on the total mass of El Gordo, ≳ 1.7 × 1015 M☉ from the SL regime alone, suggesting a total mass of roughly M200 ∼ 2.3 × 1015 M☉. Our results should be revisited when additional spectroscopic and HST imaging data are available.