Bibcode
Nipoti, Carlo; Fraternali, Filippo; Iorio, Giuliano; Di Teodoro, Enrico; Read, Justin I.; Battaglia, Giuseppina
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 466, Issue 4, p.4159-4192
Fecha de publicación:
4
2017
Número de citas
115
Número de citas referidas
99
Descripción
Dwarf irregular galaxies (dIrrs) are the smallest stellar systems with
extended H i discs. The study of the kinematics of such discs is a
powerful tool to estimate the total matter distribution at these very
small scales. In this work, we study the H i kinematics of 17 galaxies
extracted from the 'Local Irregulars That Trace Luminosity Extremes, The
H i Nearby Galaxy Survey' (LITTLE THINGS). Our approach differs
significantly from previous studies in that we directly fit 3D models
(two spatial dimensions plus one spectral dimension) using the software
3Dbarolo, fully exploiting the information in the H i data
cubes. For each galaxy, we derive the geometric parameters of the H i
disc (inclination and position angle), the radial distribution of the
surface density, the velocity-dispersion (σv) profile
and the rotation curve. The circular velocity (Vc), which
traces directly the galactic potential, is then obtained by correcting
the rotation curve for the asymmetric drift. As an initial application,
we show that these dIrrs lie on a baryonic Tully-Fisher relation in
excellent agreement with that seen on larger scales. The final products
of this work are high-quality, ready-to-use kinematic data
(Vc and σv) that we make publicly available.
These can be used to perform dynamical studies and improve our
understanding of these low-mass galaxies.
Proyectos relacionados
Evolución Galáctica en el Grupo Local
La formación y evolución de galaxias es un problema fundamental en Astrofísica. Su estudio requiere “viajar atrás en el tiempo”, para lo cual hay dos enfoques complementarios. El mas extendido consiste en analizar las propiedades de las galaxias a diferentes distancias cosmológicas. Nuestro equipo se concentra en el otro enfoque, denominado
Matteo
Monelli