# The fate of the Antennae galaxies

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http://hdl.handle.net/10138/309984

#### Citation

Lahén , N , Johansson , P H , Rantala , A , Naab , T & Frigo , M 2018 , ' The fate of the Antennae galaxies ' , Monthly Notices of the Royal Astronomical Society , vol. 475 , no. 3 , pp. 3934-3958 . https://doi.org/10.1093/mnras/sty060-

 Title: The fate of the Antennae galaxies Author: Lahén, Natalia; Johansson, Peter H.; Rantala, Antti; Naab, Thorsten; Frigo, Matteo Contributor organization: Department of Physics Date: 2018-04 Language: eng Number of pages: 25 Belongs to series: Monthly Notices of the Royal Astronomical Society ISSN: 0035-8711 DOI: https://doi.org/10.1093/mnras/sty060- URI: http://hdl.handle.net/10138/309984 Abstract: We present a high-resolution smoothed particle hydrodynamics simulation of the Antennae galaxies (NGC 4038/4039) and follow the evolution $3$ Gyrs beyond the final coalescence. The simulation includes metallicity dependent cooling, star formation, and both stellar feedback and chemical enrichment. The simulated best-match Antennae reproduces well both the observed morphology and the off-nuclear starburst. We also produce for the first time a simulated two-dimensional metallicity map of the Antennae and find good agreement with the observed metallicity of off-nuclear stellar clusters, however the nuclear metallicities are overproduced by $\sim 0.5$ dex. Using the radiative transfer code SKIRT we produce multi-wavelength observations of both the Antennae and the merger remnant. The $1$ Gyr old remnant is well fitted with a S\'ersic profile of $n=4.05$, and with an $r$-band effective radius of $r_{\mathrm{e}}= 1.8$ kpc and velocity dispersion of $\sigma_{\mathrm{e}}=180$ km$/$s the remnant is located on the fundamental plane of early-type galaxies (ETGs). The initially blue Antennae remnant evolves onto the red sequence after $\sim 2.5$ Gyr of secular evolution. The remnant would be classified as a fast rotator, as the specific angular momentum evolves from $\lambda_R\approx0.11$ to $\lambda_R\approx0.14$ during its evolution. The remnant shows ordered rotation and a double peaked maximum in the mean 2D line-of-sight velocity. These kinematical features are relatively common among local ETGs and we specifically identify three local ETGs (NGC 3226, NGC 3379 and NGC 4494) in the ATLAS$^\mathrm{3D}$ sample, whose photometric and kinematic properties most resemble the Antennae remnant.We present a high-resolution smoothed particle hydrodynamic simulation of the Antennae galaxies (NGC 4038/4039) and follow the evolution 3 Gyr beyond the final coalescence. The simulation includes metallicity-dependent cooling, star formation, and both stellar feed-back and chemical enrichment. The simulated best-match Antennae reproduce well both the observed morphology and the off-nuclear starburst. We also produce for the first time a simulated two-dimensional (2D) metallicity map of the Antennae and find good agreement with the observed metallicity of off-nuclear stellar clusters; however, the nuclear metallicities are overproduced by similar to 0.5 dex. Using the radiative transfer code SKIRT, we produce multiwavelength observations of both the Antennae and the merger remnant. The 1-Gyr-old remnant is well fitted with a Sersic profile of n = 7.07, and with an r-band effective radius of r(e) = 1.6 kpc and velocity dispersion of sigma(e) = 180 km s(-1) the remnant is located on the Fundamental Plane of early-type galaxies (ETGs). The initially blue Antennae remnant evolves on to the red sequence after similar to 2.5 Gyr of secular evolution. The remnant would be classified as a fast rotator, as the specific angular momentum evolves from lambda(Re) approximate to 0.11 to 0.14 during its evolution. The remnant shows ordered rotation and a double peaked maximum in the mean 2D line-of-sight velocity. These kinematical features are relatively common amongst local ETGs and we specifically identify three local ETGs (NGC 3226, NGC 3379, and NGC 4494) in the ATLAS(3D) sample, whose photometric and kinematic properties most resemble the Antennae remnant. Description: 27 pages, 18 figures, submitted to MNRAS Subject: astro-ph.GA RADIATIVE-TRANSFER CODE galaxies: starburst ELLIPTIC GALAXIES galaxies: evolution H-II REGIONS methods: numerical SMOOTHED PARTICLE HYDRODYNAMICS galaxies: individual: NGC 4038/4039 MASS-METALLICITY RELATION YOUNG STAR-CLUSTERS TO-LIGHT RATIO DIGITAL SKY SURVEY galaxies: kinematics and dynamics LENS ACS SURVEY ULTRALUMINOUS INFRARED GALAXIES 115 Astronomy, Space science Peer reviewed: Yes Usage restriction: openAccess Self-archived version: publishedVersion
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