HerS-3: An Exceptional Einstein Cross Reveals a Massive Dark Matter Halo
Artikel i vetenskaplig tidskrift, 2025

We present a study of HerS-3, a dusty star-forming galaxy at zspec = 3.0607, which is gravitationally amplified into an Einstein cross with a fifth image of the background galaxy seen at the center of the cross. Detailed 1 mm spectroscopy and imaging with NOEMA and the Atacama Large Millimeter/submillimeter Array resolve the individual images and show that each of the five images display a series of molecular lines that have similar central velocities, unambiguously confirming that they have identical redshifts. The Hubble Space Telescope F110W image reveals a foreground lensing group of four galaxies with a photometric redshift zphot ∼ 1.0. Lens models that only include the four visible galaxies are unable to reproduce the properties of HerS-3. By adding a fifth massive component, lying southeast of the brightest galaxy of the group, the source reconstruction is able to match the peak emission, shape, and orientation for each of the five images. The fact that no galaxy is detected near that position indicates the presence of a massive dark matter halo in the lensing galaxy group. In the source plane, HerS-3 appears as an infrared luminous starburst galaxy seen nearly edge on. The serendipitous discovery of this exceptional Einstein cross offers a potential laboratory for exploring at small spatial scales a nuclear starburst at the peak of cosmic evolution and studying the properties of a massive dark matter halo associated with the lensing galaxy group.

Författare

P. Cox

Institut d 'Astrophysique de Paris

Kirsty May Butler

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

C. R. Keeton

Rutgers University

L. Eid

Rutgers University

E. Borsato

Università di Padova

Tom Bakx

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

R. Neri

Institut de Radioastronomie Millimétrique (IRAM)

B. M. Jones

Universität zu Köln

Prachi Prajapati

Universität zu Köln

Max-Planck-Gesellschaft

A. J. Baker

University of the Western Cape

Rutgers University

S. Berta

Institut de Radioastronomie Millimétrique (IRAM)

A. Cooray

University of California

E. M. Corsini

Università di Padova

Istituto nazionale di astrofisica (INAF)

L. Marchetti

Istituto di Radioastronomia

University of Cape Town

A.A. Omont

Institut d 'Astrophysique de Paris

A. Beelen

Laboratoire d'Astrophysique de Marseille

R. Gavazzi

Laboratoire d'Astrophysique de Marseille

D. Ismail

Observatoire Astronomique de Strasbourg

R. J. Ivison

University of Edinburgh

Dublin Institute for Advanced Studies

M. Krips

Institut de Radioastronomie Millimétrique (IRAM)

M. Lehnert

Université de Lyon

Institut d 'Astrophysique de Paris

H. Messias

Atacama Large Millimeter-submillimeter Array (ALMA)

European Southern Observatory Santiago

D. A. Riechers

Universität zu Köln

C. Vlahakis

National Radio Astronomy Observatory

A. Weiß

Max-Planck-Gesellschaft

P. van der Werf

Universiteit Leiden

Chentao Yang

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

Astrophysical Journal

0004-637X (ISSN) 1538-4357 (eISSN)

Vol. 991 1 53

The Origin and Fate of Dust in Our Universe

Knut och Alice Wallenbergs Stiftelse (KAW 2019.0443), 2020-06-01 -- 2023-05-31.

Knut och Alice Wallenbergs Stiftelse (KAW 2020.0081), 2021-07-01 -- 2026-06-30.

Ämneskategorier (SSIF 2025)

Astronomi, astrofysik och kosmologi

DOI

10.3847/1538-4357/adf204

Mer information

Senast uppdaterat

2025-09-26