Person: Alcalde Pampliega, Belén
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First Name
Belén
Last Name
Alcalde Pampliega
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Físicas
Department
Física de la Tierra y Astrofísica
Area
Física de la Tierra
Identifiers
6 results
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Now showing 1 - 6 of 6
Item Shards: a global view of the star formation activity at z ~ 0.84 and z ~ 1.23(Astrophysical journal, 2015) Pérez González, Pablo Guillermo; Eliche Moral, María del Carmen; Alcalde Pampliega, Belén; Cardiel López, Nicolás; Domínguez Sánchez, Helena; Espino Briones, Néstor; Esquej Alonso, María del Pilar; Gallego Maestro, Jesús; Rodríguez Muñoz, LucíaIn this paper, we present a comprehensive analysis of star-forming galaxies (SFGs) at intermediate redshifts (z ~ 1). We combine the ultra-deep optical spectro-photometric data from the Survey for High-z Absorption Red and Dead Sources (SHARDS) with deep UV-to-FIR observations in the GOODS-N field. Exploiting two of the 25 SHARDS medium-band filters, F687W17 and F823W17, we select [O II] emission line galaxies at z ~ 0.84 and z ~ 1.23 and characterize their physical properties. Their rest-frame equivalent widths (EWrf([O ii])), line fluxes, luminosities, star formation rates (SFRs), and dust attenuation properties are investigated. The evolution of EW_rf([O II]) closely follows the SFR density evolution of the universe, with a trend of EW_rf([O II]) ∞ (1 + z)^3 up to redshift z ≃1, followed by a possible flattening. The SF properties of the galaxies selected on the basis of their [O II] emission are compared with complementary samples of SFGs selected by their MIR and FIR emission, and also with a general mass-selected sample of galaxies at the same redshifts. We demonstrate observationally that the UVJ diagram (or, similarly, a cut in the specific SFR) is only partially able to distinguish the quiescent galaxies from the SFGs. The SFR–M_* relation is investigated for the different samples, yielding a logarithmic slope ~1, in good agreement with previous results. The dust attenuations derived from different SFR indicators (UV(1600), UV(2800), [O II], IR) are compared and show clear trends with respect to both the stellar mass and total SFR, with more massive and highly star-forming galaxies being affected by stronger dust attenuation.Item A duality in the origin of bulges and spheroidal galaxies(Astrophysical journal, 2021) Costantin, Luca; Pérez González, Pablo Guillermo; Méndez Abreu, Jairo; Huertas Company, Marc; Dimauro, Paola; Alcalde Pampliega, Belén; Buitrago, Fernando; Ceverino, Daniel; Daddi, Emanuele; Domínguez Sánchez, Helena; Espino Briones, Néstor; Hernán Caballero, Antonio; Koekemoer, Anton M.; Rodighiero, GiuliaStudying the resolved stellar populations of the different structural components which build massive galaxies directly unveils their assembly history. We aim at characterizing the stellar population properties of a representative sample of bulges and pure spheroids in massive galaxies (M* > 10^(10) Mסּ ) in the GOODS-N field. We take advantage of the spectral and spatial information provided by SHARDS and HST data to perform the multi-image spectro-photometrical decoupling of the galaxy light. We derive the spectral energy distribution separately for bulges and disks in the redshift range 0.14 < z ≤1 with spectral resolution R ∼50. Analyzing these SEDs, we find evidences of a bimodal distribution of bulge formation redshifts. We find that 33% of them present old mass-weighted ages, implying a median formation redshift z_(form) = 6.2^(+1.5)_(−1.7). They are relics of the early Universe embedded in disk galaxies. A second wave, dominant in number, accounts for bulges formed at median redshift z_(form) = 1.3^(+0.6)_(−0.6). The oldest (1st-wave) bulges are more compact than the youngest. Virtually all pure spheroids (i.e., those without any disk) are coetaneous with the 2nd-wave bulges, presenting a median redshift of formation z_(form) = 1.1^(+0.3)_(−0.3). The two waves of bulge formation are not only distinguishable in terms of stellar ages, but also in star formation mode. All 1st-wave bulges formed fast at z ∼ 6, with typical timescales around 200 Myr. A significant fraction of the 2nd-wave bulges assembled more slowly, with star formation timescales as long as 1 Gyr. The results of this work suggest that the centers of massive disk-like galaxies actually harbor the oldest spheroids formed in the Universe.Item SHARDS: constraints on the dust attenuation law of star-forming galaxies at z∼2(Monthly notices of the Royal Astronomical Society, 2018) Pérez González, Pablo Guillermo; Alcalde Pampliega, Belén; Domínguez Sánchez, Helena; Eliche Moral, María del Carmen; Espino Briones, Néstor; Hernán Caballero, AntonioWe make use of the Survey of High-z Absorption Red and Dead Sources, an ultradeep (<26.5AB) galaxy survey that provides optical photospectra at resolution R similar to 50, via medium-band filters (FWHM similar to 150 angstrom). This data set is combined with ancillary optical and NIR fluxes to constrain the dust attenuation law in the rest-frame NUV region of star-forming galaxies within the redshift window 1.5 < z < 3. We focus on the NUV bump strength (B) and the total-to-selective extinction ratio (R-V), targeting a sample of 1753 galaxies. By comparing the data with a set of population synthesis models coupled to a parametric dust attenuation law, we constrain R-V and B, as well as the colour excess, E(B - V). We find a correlation between R-V and B, which can be interpreted either as a result of the grain size distribution, or a variation of the dust geometry among galaxies. According to the former, small dust grains are associated with a stronger NUV bump. The latter would lead to a range of clumpiness in the distribution of dust within the interstellar medium of star-forming galaxies. The observed wide range of NUV bump strengths can lead to a systematic in the interpretation of the UV slope beta typically used to characterize the dust content. In this study, we quantify these variations, concluding that the effects are Delta beta similar to 0.4.Item Optically faint massive Balmer break galaxies at z > 3 in the CANDELS/GOODS fields(Astrophysical journal, 2019) Alcalde Pampliega, Belén; Pérez González, Pablo Guillermo; Barro, Guillermo; Domínguez Sánchez, Helena; Eliche Moral, M. Carmen; Cardiel López, Nicolás; Hernán Caballero, Antonio; Rodríguez Muñoz, Lucía; Sánchez Blázquez, Patricia; Esquej, PilarWe present a sample of 33 Balmer break galaxies (BBGs) selected as Hubble Space Telescope/F160W dropouts in the deepest CANDELS/GOODS fields (H >/~ 27.3 mag) but relatively bright in Spitzer/IRAC ([3.6], [4.5] < 24.5 mag), implying red colors (median and quartiles: {H - [3.6]} = 3.1^(3.4)_(2.8) mag ). Half of these BBGs are newly identified sources. Our BBGs are massive ({ log (M/ M_(☉))} = 10.8_(10.4)^( 11.0)), high-redshift ({z} = 4.8_(4.4)^(5.1)), dusty ({A(V)} = 2.0_(1.5)^(2.0) mag) galaxies. The spectral energy distributions (SEDs) of half of our sample indicate that they are star-forming galaxies with typical specific star formation rates (SFRs) of 0.5–1.0 Gyr^(−1), qualifying them as main-sequence (MS) galaxies at 3 < z < 6. One-third of these SEDs indicate the presence of prominent emission lines (Hβ + [O III], Hα + [N II]) boosting the IRAC fluxes and red colors. Approximately 20% of the BBGs are very dusty (A (V) ∼ 2.5 mag) starbursts with strong mid-to-far-infrared detections and extreme SFRs (SFR > 10^(3) M_(☉) yr^(−1)) that place them above the MS. The rest, 30%, are post-starbursts or quiescent galaxies located >2σ below the MS with mass-weighted ages older than 700 Myr. Only two of the 33 galaxies are X-ray-detected active galactic nuclei (AGNs) with optical/near-infrared SEDs dominated by stellar emission, but the presence of obscured AGNs in the rest of the sources cannot be discarded. Our sample accounts for 8% of the total number density of log(M / M_(☉)) > 10 galaxies at z > 3, but it is a significant contributor (30%) to the general population of red log(M / M_(☉) > 11 galaxies at 4 < z < 6. Finally, our results point out that one of every 30 massive log (M / M_(☉) > 11 galaxies in the local universe was assembled in the first 1.5 Gyr after the big bang, a fraction that is not reproduced by state-of-the-art galaxy formation simulations.Item From Naked Spheroids to Disky Galaxies: How Do Massive Disk Galaxies Shape Their Morphology?(Astrophysical journal, 2022) Costantin, Luca; Pérez González, Pablo Guillermo; Méndez Abreu, Jairo; Huertas Company, Marc; Alcalde Pampliega, Belén; Balcells, Marc; Barro, Guillermo; Ceverino, Daniel; Dimauro, Paola; Domínguez Sánchez, Helena; Espino Briones, Néstor; Koekemoer, Anton M.We investigate the assembly history of massive disk galaxies and describe how they shape their morphology through cosmic time. Using SHARDS and HST data, we modeled the surface brightness distribution of 91 massive galaxies at redshift 0.14 < z <= 1 in the wavelength range 0.5-1.6 mu m, deriving the uncontaminated spectral energy distributions of their bulges and disks separately. This spectrophotometric decomposition allows us to compare the stellar population properties of each component in individual galaxies. We find that the majority of massive galaxies (similar to 85%) build inside-out, growing their extended stellar disk around the central spheroid. Some bulges and disks could start forming at similar epochs, but these bulges grow more rapidly than their disks, assembling 80% of their mass in similar to 0.7 and similar to 3.5 Gyr, respectively. Moreover, we infer that both older bulges and older disks are more massive and compact than younger stellar structures. In particular, we find that bulges display a bimodal distribution of mass-weighted ages; i.e., they form in two waves. In contrast, our analysis of the disk components indicates that they form at z similar to 1 for both first- and second-wave bulges. This translates to first-wave bulges taking longer to acquire a stellar disk (5.2 Gyr) compared to second-wave, less compact spheroids (0.7 Gyr). We do not find distinct properties (e.g., mass, star formation timescale, and mass surface density) for the disks in both types of galaxies. We conclude that the bulge mass and compactness mainly regulate the timing of the stellar disk growth, driving the morphological evolution of massive disk galaxies.Item Pathways to quiescence: SHARDS view on the star formation histories of massive quiescent galaxies at 1.0 < z < 1.5(Monthly notices of the Royal Astronomical Society, 2016) Domínguez Sánchez, Helena; Pérez González, Pablo Guillermo; Esquej Alonso, María del Pilar; Eliche Moral, María del Carmen; Alcalde Pampliega, Belén; Cardiel López, NicolásWe present star formation histories (SFHs) for a sample of 104 massive (stellar mass M > 10^10 M_⊙) quiescent galaxies (MQGs) at z = 1.0–1.5 from the analysis of spectrophotometric data from the Survey for High-z Absorption Red and Dead Sources (SHARDS) and HST/WFC3 G102 and G141 surveys of the GOODS-North field, jointly with broad-band observations from ultraviolet (UV) to far-infrared (far-IR). The sample is constructed on the basis of rest-frame UVJ colours and specific star formation rates (sSFRs = SFR/Mass). The spectral energy distributions (SEDs) of each galaxy are compared to models assuming a delayed exponentially declining SFH. A Monte Carlo algorithm characterizes the degeneracies, which we are able to break taking advantage of the SHARDS data resolution, by measuring indices such as MgUV and D4000. The population of MQGs shows a duality in their properties. The sample is dominated (85 per cent) by galaxies with young mass-weighted ages, t_M t_M < 2 Gyr, short star formation time-scales, 〈τ〉 ∼ 60–200 Myr, and masses log(M/M_⊙) ∼ 10.5. There is an older population (15 per cent) with t_M t_M = 2–4 Gyr, longer star formation time-scales, 〈τ〉∼ 400 Myr, and larger masses, log(M/M_⊙) ∼ 10.7. The SFHs of our MQGs are consistent with the slope and the location of the main sequence of star-forming galaxies at z > 1.0, when our galaxies were 0.5–1.0 Gyr old. According to these SFHs, all the MQGs experienced a luminous infrared galaxy phase that lasts for ∼500 Myr, and half of them an ultraluminous infrared galaxy phase for ∼100 Myr. We find that the MQG population is almost assembled at z ∼ 1, and continues evolving passively with few additions to the population.