Banerji, Manda, Ferreras, Ignacio, Abdalla, Filipe B., Hewett, Paul, Lahav, Ofer
We present an analysis of the evolution of 8625 Luminous Red Galaxies between z = 0.4 and z = 0.8 in the 2dF and SDSS LRG and QSO (2SLAQ) survey. The LRGs are split into redshift bins and the...
Tidal Dwarf Galaxies around a Post-merger Galaxy, NGC 4922 (2009)
Sheen, Yun-Kyeong, Jeong, Hyunjin, Yi, Sukyoung K., Ferreras, Ignacio, Lotz, Jennifer M., Olsen, Knut A. G., ...
One possible channel for the formation of dwarf galaxies involves birth in the tidal tails of interacting galaxies. We report the detection of a bright UV tidal tail and several young tidal dwarf...
Early-type galaxies in the PEARS survey: Probing the stellar populations at moderate redshift (2009)
Ferreras, Ignacio, Pasquali, Anna, Malhotra, Sangeeta, Rhoads, James, Cohen, Seth, Windhorst, Rogier, ...
Using HST/ACS slitless grism spectra from the PEARS program, we study the stellar populations of morphologically selected early-type galaxies in the GOODS North and South fields. The sample -...
Incompatibility of Rotation Curves with Gravitational Lensing for TeVeS (2009)
Ferreras, Ignacio, Mavromatos, Nick E., Sakellariadou, Mairi, Yusaf, Muhammad Furqaan
We constrain the one-parameter class of TeVeS models by testing the theory against both rotation curve and strong gravitational lensing data on galactic scales, remaining fully relativistic in our...
Could the Galactic disk heating be due to Globular Cluster impacts? (2009)
Putte, D. Vande, Cropper, Mark, Ferreras, Ignacio
So far, six mechanisms have been proposed to account for the Galactic disk heating. Of these, the most important appear to be a combination of scattering of stars by molecular clouds and by spiral...
Star formation and nuclear activity in close pairs of early-type galaxies (2009)
Rogers, Ben, Ferreras, Ignacio, Kaviraj, Sugata, Pasquali, Anna, Sarzi, Marc
We extract from the Sloan Digital Sky Survey a sample of 347 systems involving early type galaxies separated by less than 30 kpc, in projection, and 500 km/s in radial velocity. These close pairs are...
Ferreras, Ignacio, Lisker, Thorsten, Pasquali, Anna, Khochfar, Sadegh, Kaviraj, Sugata
The evolution of number density, size and intrinsic colour is determined for a volume-limited sample of visually classified early-type galaxies selected from the HST/ACS images of the GOODS North and...
Peletier, Reynier F., Ferreras, Ignacio, Rogers, Ben, Silk, Joseph
We study the stellar populations of 14 elliptical galaxies in the Virgo cluster. We propose an alternative approach to the standard side-band method to measure equivalent widths (EWs). Our Boosted...
Exploring the formation of spheroidal galaxies out to z~1.5 in GOODS (2009)
Ferreras, Ignacio, Lisker, Thorsten, Pasquali, Anna, Kaviraj, Sugata
(Abridged) The formation of massive spheroidal galaxies is studied on a visually classified sample of 910 galaxies extracted from the ACS/HST images of the GOODS North and South fields (0.4
Rogers, Ben, Ferreras, Ignacio, Peletier, Reynier F., Silk, Joseph
(Abridged) We study the stellar populations of 14 elliptical galaxies in the Virgo cluster. We propose an alternative approach to the standard side-band method to measure equivalent widths (EWs). Our...
Buyle, Pieter, De Rijcke, Sven, Debattista, Victor P., Ferreras, Ignacio, Pasquali, Anna, Seth, Anil, ...
The presence of black holes (BHs) at the centers of dwarf elliptical galaxies (dEs) has been argued both theoretically and observationally. Using archival HST/WFPC2 data, we found the Virgo cluster...
Buyle, Pieter, De Rijcke, Sven, Debattista, Victor P., Ferreras, Ignacio, Pasquali, Anna, Seth, Anil, ...
Towards a Solution for the Ca II Triplet Puzzle : Results from Dwarf Elliptical Galaxies (2007)
Michielsen, Dolf, Koleva, Mina, Prugniel, Philippe, Zeilinger, Werner W., De Rijcke, Sven, Dejonghe, Herwig, ...
We present new estimates of ages and metallicities, based on FORS/VLT optical (4400-5500A) spectroscopy, of 16 dwarf elliptical galaxies (dE's) in the Fornax Cluster and in Southern Groups. These...
Unveiling dark halos in lensing galaxies (2007)
Ferreras, Ignacio, Saha, Prasenjit, Burles, Scott
We present a spatially resolved comparison of the stellar-mass and total-mass surface distributions of nine early-type galaxies. The galaxies are a subset of the Sloan Lens ACS survey (or SLACS;...
The necessity of dark matter in MOND within galactic scales (2007)
Ferreras, Ignacio, Sakellariadou, Mairi, Yusaf, Muhammad Furqaan
To further test MOdified Newtonian Dynamics (MOND) on galactic scales -- originally proposed to explain the rotation curves of disk galaxies without dark matter -- we study a sample of six strong...
Rogers, Ben, Ferreras, Ignacio, Lahav, Ofer, Bernardi, Mariangela, Kaviraj, Sugata, Yi, Sukyoung K.
(Abridged) We apply Principal Component Analysis (PCA) to a sample of early-type galaxies from the Sloan Digital Sky Survey (SDSS) in order to infer differences in their star formation histories. Out...
Toward a solution for the Ca II triplet puzzle: results from dwarf elliptical galaxies (2007)
Michielsen, Dolf, Koleva, Mina, Prugniel, Philippe, Zeilinger, Werner W., De Rijcke, Sven, Dejonghe, Herwig, ...
We present new estimates of ages and metallicities, based on VLT FORS optical (4400-5500 Å) spectroscopy, of 16 dwarf elliptical galaxies (dE's) in the Fornax Cluster and in southern groups. These...
Debattista, Victor P., Ferreras, Ignacio, Pasquali, Anna, Seth, Anil, De Rijcke, Sven, Morelli, Lorenzo
{\it Hubble Space Telescope} (\hst) Wide Field Planetary Camera 2 ({\it WFPC2}) images of the Virgo Cluster dwarf elliptical galaxy VCC 128 reveal an apparently double nucleus. The two components,...
Double-barred galaxies at intermediate redshifts: a feasibility study (2006)
Lisker, Thorsten, Debattista, Victor P., Ferreras, Ignacio, Erwin, Peter
Ferreras, Ignacio, Pasquali, Anna, De Carvalho, Reinaldo R., De La Rosa, Ignacio G., Lahav, Ofer
Environmental differences in the stellar populations of early-type galaxies are explored using principal component analysis (PCA), focusing on differences between elliptical galaxies in Hickson...
Debattista, Victor P., Ferreras, Ignacio, Pasquali, Anna, Seth, Anil, De Rijcke, Sven, Morelli, Lorenzo
Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC2) images of the Virgo Cluster dwarf elliptical galaxy VCC 128 reveal an apparently double nucleus. The two components, which are...
Massive elliptical galaxies : From cores to haloes (2005)
Lintott, Chris, Ferreras, Ignacio, Lahav, Ofer
In the context of recent observational results that show massive ellipticals were in place at high redshifts, we reassess the status of monolithic collapse in a LCDM universe. Using a sample of over...
Double barred galaxies at intermediate redshifts: A feasibility study (2005)
Lisker, Thorsten, Debattista, Victor P., Ferreras, Ignacio, Erwin, Peter
Despite the increasing number of studies of barred galaxies at intermediate and high redshifts, double-barred (S2B) systems have only been identified in the nearby (z
Stellar and total mass in early-type lensing galaxies (2005)
Ferreras, Ignacio, Saha, Prasenjit, Williams, Liliya L. R.
For 18 well-observed gravitationally lensed QSOs, we compare new non-parametric mass profiles for the lensing galaxies with stellar-population models derived from published HST photometry. The large...
Kaviraj, Sugata, Devriendt, Julien E. G., Ferreras, Ignacio, Yi, Sukyoung K.
The colour-magnitude relation (CMR) of cluster ellipticals has been widely used to constrain their star formation histories (SFHs) and to discriminate between the monolithic and merger paradigms of...
Using bright ellipticals as dark energy cosmic clocks (2003)
Ferreras, Ignacio, Melchiorri, Alessandro, Tocchini-Valentini, Domenico
The age of the Universe has been increasingly constrained by different techniques such as the observations of type Ia supernovae at high redshift or dating the stellar populations of globular...
Near and far: the star formation history of disk galaxies Elektronische Daten (2003)
Ferreras, Ignacio, Silk, Joseph, Astrophysics Conference
Talk Abstract von Kongress: Star and Structure Formation: From First Light to the Milky Way, Astrophysics Conference, August 18-22, 2003, ETH Zurich, Switzerland
Type Ia supernovae and the formation history of early-type galaxies (2002)
Ferreras, Ignacio, Silk, Joseph
Using the standard prescription for the rates of supernovae type II and type Ia, we compare the predictions of a simple model of star formation in galaxies with the observed radial gradients of...
Feedback Processes in Early-Type Galaxies (2002)
Ferreras, Ignacio, Scannapieco, Evan, Silk, Joseph
We present a phenomenological model of feedback in early-type galaxies that tracks the evolution of the interstellar medium gas mass, metallicity, and temperature. Modeling the star formation rate as...