The SAMI — Fornax Dwarfs Survey I: Sample, observations and the specific stellar angular momentum of dwarf elliptical galaxies. (arXiv:2007.04492v1 [astro-ph.GA])

The SAMI — Fornax Dwarfs Survey I: Sample, observations and the specific stellar angular momentum of dwarf elliptical galaxies. (arXiv:2007.04492v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Scott_N/0/1/0/all/0/1">Nicholas Scott</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Eftekhari_F/0/1/0/all/0/1">F. Sara Eftekhari</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Peletier_R/0/1/0/all/0/1">Reynier F. Peletier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bryant_J/0/1/0/all/0/1">Julia J. Bryant</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bland_Hawthorn_J/0/1/0/all/0/1">Joss Bland-Hawthorn</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Capaccioli_M/0/1/0/all/0/1">Massimo Capaccioli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Croom_S/0/1/0/all/0/1">Scott M. Croom</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Drinkwater_M/0/1/0/all/0/1">Michael Drinkwater</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Falcon_Barroso_J/0/1/0/all/0/1">Jesus Falcon-Barroso</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hilker_M/0/1/0/all/0/1">Michael Hilker</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Iodice_E/0/1/0/all/0/1">Enrichetta Iodice</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lorente_N/0/1/0/all/0/1">Nuria F. P. Lorente</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mieske_S/0/1/0/all/0/1">Steffen Mieske</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Spavone_M/0/1/0/all/0/1">Marilena Spavone</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ven_G/0/1/0/all/0/1">Glenn van de Ven</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Venhola_A/0/1/0/all/0/1">Aku Venhola</a>

Dwarf ellipticals are the most common galaxy type in cluster environments,
however the challenges associated with their observation mean their formation
mechanisms are still poorly understood. To address this, we present deep
integral field observations of a sample of 31 low-mass ($10^{7.5} <$ M$_star <
10^{9.5}$ M$_odot$) early-type galaxies in the Fornax cluster with the SAMI
instrument. For 21 galaxies our observations are sufficiently deep to construct
spatially resolved maps of the stellar velocity and velocity dispersion – for
the remaining galaxies we extract global velocities and dispersions from
aperture spectra only. From the kinematic maps we measure the specific stellar
angular momentum $lambda_R$ of the lowest mass dE galaxies to date. Combining
our observations with early-type galaxy data from the literature spanning a
large range in stellar mass, we find that $lambda_R$ decreases towards lower
stellar mass, with a corresponding increase in the proportion of slowly
rotating galaxies in this regime. The decrease of $lambda_R$ with mass in our
sample dE galaxies is consistent with a similar trend seen in somewhat more
massive spiral galaxies from the CALIFA survey. This suggests that the degree
of dynamical heating required to produce dEs from low-mass starforming
progenitors may be relatively modest, and consistent with a broad range of
formation mechanisms.

Dwarf ellipticals are the most common galaxy type in cluster environments,
however the challenges associated with their observation mean their formation
mechanisms are still poorly understood. To address this, we present deep
integral field observations of a sample of 31 low-mass ($10^{7.5} <$ M$_star <
10^{9.5}$ M$_odot$) early-type galaxies in the Fornax cluster with the SAMI
instrument. For 21 galaxies our observations are sufficiently deep to construct
spatially resolved maps of the stellar velocity and velocity dispersion – for
the remaining galaxies we extract global velocities and dispersions from
aperture spectra only. From the kinematic maps we measure the specific stellar
angular momentum $lambda_R$ of the lowest mass dE galaxies to date. Combining
our observations with early-type galaxy data from the literature spanning a
large range in stellar mass, we find that $lambda_R$ decreases towards lower
stellar mass, with a corresponding increase in the proportion of slowly
rotating galaxies in this regime. The decrease of $lambda_R$ with mass in our
sample dE galaxies is consistent with a similar trend seen in somewhat more
massive spiral galaxies from the CALIFA survey. This suggests that the degree
of dynamical heating required to produce dEs from low-mass starforming
progenitors may be relatively modest, and consistent with a broad range of
formation mechanisms.

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