Bibcode
Tapia, T.; Eliche-Moral, M. C.; Aceves, Héctor; Rodríguez-Pérez, Cristina; Borlaff, A.; Querejeta, Miguel
Referencia bibliográfica
Astronomy and Astrophysics, Volume 604, id.A105, 20 pp.
Fecha de publicación:
8
2017
Revista
Número de citas
43
Número de citas referidas
42
Descripción
Context. Lenticular (S0) galaxies are known to derive from spiral
galaxies. The fact that S0s nearly obey the Tully-Fisher relation (TFR)
at z ∼ 0 (as spirals have done in the last 9 Gyr) is considered an
argument against their major-merger origin because equal mergers of two
disc galaxies produce remnants that are outliers of the TFR.
Aims: We explore whether a scenario that combines an origin by mergers
at z ∼ 1.8 - 1.5 with a subsequent passive evolution of the resulting S0
remnants since z ∼ 0.8-1 is compatible with observational data of S0s in
the TFR both at z ∼ 0.8 and z ∼ 0. Methods: We studied a set of
major and minor merger experiments from the GalMer database that
generate massive S0 remnants that are dynamically relaxed and have
realistic properties. We analysed the location of these remnants in the
photometric and stellar TFRs assuming that they correspond to z ∼ 0.8
galaxies. We then estimated their evolution in these planes over the
last 7 Gyr considering that they have evolved passively in isolation.
The results were compared with data of real S0s and spirals at different
redshifts. We also tested how the use of Vcirc or
Vrot,max affects the results. Results: Just after 1-2
Gyr of coalescence, major mergers generate S0 remnants that are outliers
of the local photometric and stellar TFRs (as already stated in previous
studies), in good agreement with observations at z ∼ 0.8. After 4-7 Gyr
of passive evolution in isolation, the S0 remnants move towards the
local TFR, although the initial scatter among them persists. This
scatter is sensitive to the indicator used for the rotation velocity:
Vcirc values yield a lower scatter than when
Vrot,max values are considered instead. In the planes
involving Vrot,max, a clear segregation of the S0 remnants in
terms of the spin-orbit coupling of the model is observed, in which the
remnants of retrograde encounters overlap with local S0s hosting
counter-rotating discs. The location of the S0 remnants at z ∼ 0 agrees
well with the observed distribution of local S0 galaxies in the
σ0-MK, Vcirc-σ0,
and Vrot,max-σ0 planes. Conclusions:
Massive S0 galaxies may have been formed through major mergers that
occurred at high redshift and have later evolved towards the local TFR
through passive evolution in relative isolation, a mechanism that would
also contribute to the scatter observed in this relation.
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Estudios Cinemáticos, Estructurales y de Composición, de los Medios Interestelares e Intergalácticos
El objetivo básico del proyecto es investigar la evolución de las galaxias mediante el entendimiento de la interacción del medio interestelar y las estrellas. La técnica principal que utilizamos es la cinemática bidimensional de galaxias enteras observada por nuestro instrumento GHaFaS, un interferometro Fabry Perot en el telescopio William
Prof.
John E. Beckman