TY - JOUR

T1 - A strong lensing model of the galaxy cluster PSZ1 G311.65-18.48

AU - Pignataro, G. V.

AU - Bergamini, P.

AU - Meneghetti, M.

AU - Vanzella, E.

AU - Calura, F.

AU - Grillo, C.

AU - Rosati, P.

AU - Angora, G.

AU - Brammer, G.

AU - Caminha, G. B.

AU - Mercurio, A.

AU - Nonino, M.

AU - Tozzi, P.

PY - 2021/11/24

Y1 - 2021/11/24

N2 - We present a strong lensing analysis of the galaxy cluster PSZ1 G311.65-18.48 (z = 0.443) using multi-band observations with Hubble Space Telescope complemented with VLT /MUSE spectroscopic data. The MUSE observations provide redshift estimates for the lensed sources and help to reduce misidentification of the multiple images. Spectroscopic data are also used to measure the inner velocity dispersions of 15 cluster galaxies and calibrate the scaling relations to model the subhalo cluster component. The model is based on 62 multiple images grouped in 17 families belonging to four different sources. The majority of them are multiple images of compact stellar knots belonging to a single star-forming galaxy at z = 2.3702. This source is strongly lensed by the cluster to form the Sunburst Arc system. To accurately reproduce all the multiple images, we built a parametric mass model, which includes both cluster-scale and galaxy-scale components. The resulting model has a rms separation between the model-predicted and the observed positions of the multiple images of only 0.1400. We conclude that PSZ1 G311.65-18.48 has a relatively round projected shape and a large Einstein radius (2900 for zs = 2.3702), which could indicate that the cluster is elongated along the line of sight. The Sunburst Arc source is located at the intersection of a complex network of caustics, which explains why parts of the arc are imaged with unprecedented multiplicity (up to 12 times).

AB - We present a strong lensing analysis of the galaxy cluster PSZ1 G311.65-18.48 (z = 0.443) using multi-band observations with Hubble Space Telescope complemented with VLT /MUSE spectroscopic data. The MUSE observations provide redshift estimates for the lensed sources and help to reduce misidentification of the multiple images. Spectroscopic data are also used to measure the inner velocity dispersions of 15 cluster galaxies and calibrate the scaling relations to model the subhalo cluster component. The model is based on 62 multiple images grouped in 17 families belonging to four different sources. The majority of them are multiple images of compact stellar knots belonging to a single star-forming galaxy at z = 2.3702. This source is strongly lensed by the cluster to form the Sunburst Arc system. To accurately reproduce all the multiple images, we built a parametric mass model, which includes both cluster-scale and galaxy-scale components. The resulting model has a rms separation between the model-predicted and the observed positions of the multiple images of only 0.1400. We conclude that PSZ1 G311.65-18.48 has a relatively round projected shape and a large Einstein radius (2900 for zs = 2.3702), which could indicate that the cluster is elongated along the line of sight. The Sunburst Arc source is located at the intersection of a complex network of caustics, which explains why parts of the arc are imaged with unprecedented multiplicity (up to 12 times).

KW - galaxies: clusters: general

KW - gravitational lensing: strong

KW - cosmology: observations

KW - dark matter

KW - galaxies: kinematics and dynamics

KW - STAR-FORMATION

KW - ARC

KW - SUBSTRUCTURE

KW - HALO

KW - SIMULATIONS

KW - RESOLUTION

KW - STELLAR

KW - Z=2.481

KW - LENSES

U2 - 10.1051/0004-6361/202141586

DO - 10.1051/0004-6361/202141586

M3 - Journal article

VL - 655

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

SN - 0004-6361

M1 - A81

ER -