Person:
Zamorano Calvo, Jaime

First Name

Jaime

Last Name

Zamorano Calvo

URI

https://hdl.handle.net/20.500.14352/74989

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Físicas

Department

Física de la Tierra y Astrofísica

Area

Astronomía y Astrofísica

Identifiers

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Now showing 1 - 10 of 18

On the nature of the extragalactic number counts in the K-band
(Astronomy & Astrophysics, 2009) Barro, G.; Gallego Maestro, Jesús; Pérez González, Pablo Guillermo; Eliche Moral, María del Carmen; Balcells, M.; Villar, V.; Cardiel López, Nicolás; Cristobal Hornillos, D.; Gil de Paz, Armando; Guzmán, R.; Pello, R.; Prieto, M.; Zamorano Calvo, Jaime
Context. The galaxy number counts has been traditionally used to test models of galaxy evolution. However, the origin of significant differences in the shape of number counts at different wavelengths is still unclear. By relating the most remarkable features in the number counts with the underlying galaxy population it is possible to introduce further constraints on galaxy evolution. Aims. We aim to investigate the causes of the different shape of the K-band number counts when compared to other bands, analyzing in detail the presence of a change in the slope around K similar to 17.5. Methods. We present a near-infrared imaging survey, conducted at the 3.5 m telescope of the Calar Alto Spanish-German Astronomical Center (CAHA), covering two separated fields centered on the HFDN and the Groth field, with a total combined area of similar to 0.27 deg(2) to a depth of K similar to 19 (3 sigma, Vega). By combining our data with public deep K-band images in the CDFS (GOODS/ISAAC) and high quality imaging in multiple bands, we extract K-selected catalogs characterized with highly reliable photometric redshift estimates. We derive redshift binned number counts, comparing the results in our three fields to sample the effects of cosmic variance. We derive luminosity functions from the observed K-band in the redshift range [0.25-1.25], that are combined with data from the references in multiple bands and redshifts, to build up the K-band number count distribution. Results. The overall shape of the number counts can be grouped into three regimes: the classic Euclidean slope regime (d log N/dm similar to 0.6) at bright magnitudes; a transition regime at intermediate magnitudes, dominated by M* galaxies at the redshift that maximizes the product phi*dVc/d Omega; and an alpha dominated regime at faint magnitudes, where the slope asymptotically approaches -0.4(alpha + 1) controlled by post-M* galaxies. The slope of the K-band number counts presents an averaged decrement of similar to 50% in the range 15.5 < K < 18.5 (d log N/dm similar to 0.6-0.30). The rate of change in the slope is highly sensitive to cosmic variance effects. The decreasing trend is the consequence of a prominent decrease of the characteristic density phi(K,obs)* (similar to 60% from z = 0.5 to z = 1.5) and an almost flat evolution of M(K,obs)* (1 sigma compatible with M(K,obs)* = -22.89 +/- 0.25 in the same redshift range).
The stellar mass assembly of galaxies from z=0 to z=4: Analysis of a sample selected in the rest-frame near-infrared with Spitzer
(Astrophysical journal, 2008) Pérez González, Pablo Guillermo; Rieke, George H.;, George H.; Villar, Victor; Barro, Guillermo; Blaylock, Myra; Egami, Eiichi; Gallego Maestro, Jesús; Gil de Paz, Armando; Pascual, Sergio; Zamorano Calvo, Jaime; Donley, Jennifer L.
Using a sample of ~28,000 sources selected at 3.6-4.5 μm with Spitzer observations of the Hubble Deep Field North, the Chandra Deep Field South, and the Lockman Hole (surveyed area ~664 arcmin^2), we study the evolution of the stellar mass content of the universe at 0 < z < 4. We calculate stellar masses and photometric redshifts, based on ~2000 templates built with stellar population and dust emission models fitting the ultraviolet to mid-infrared spectral energy distributions of galaxies with spectroscopic redshifts. We estimate stellar mass functions for different redshift intervals. We find that 50% of the local stellar mass density was assembled at 0 < z < 1 (average star formation rate [SFR] 0.048 M-☉ yr^−1 Mpc^−3), and at least another 40% at 1 < z < 4 (average SFR 0.074 M_☉ yr^−1 Mpc^−3). Our results confirm and quantify the "downsizing" scenario of galaxy formation. The most massive galaxies (M > 10^12.0 M_☉) assembled the bulk of their stellar content rapidly (in 1-2 Gyr) beyond z ~ 3 in very intense star formation events (producing high specific SFRs). Galaxies with 10^11.5 < M < 10^12.0 M_☉ assembled half of their stellar mass before z ~ 1.5, and more than 90% of their mass was already in place at z ~ 0.6. Galaxies with M < 1011.5 M☉ evolved more slowly (presenting smaller specific SFRs), assembling half of their stellar mass below z ~ 1. About 40% of the local stellar mass density of 10^9.0 < M < 10^11.0 M_☉ galaxies was assembled below z ~ 0.4, most probably through accretion of small satellites producing little star formation. The cosmic stellar mass density at z > 2.5 is dominated by optically faint (Rgsim 25) red galaxies (distant red galaxies or BzK sources), which account for ~30% of the global population of galaxies, but contribute at least 60% of the cosmic stellar mass density. Bluer galaxies (e.g., Lyman break galaxies) are more numerous but less massive, contributing less than 50% of the global stellar mass density at high redshift.
CO^(12) mapping of the low-metallicity blue compact dwarf galaxy Markarian 86
(Astrophysical journal, 2002) Gil de Paz, Armando; Silich, S. A.; Madore, B. F.; Sánchez Contreras, C.; Zamorano Calvo, Jaime; Gallego Maestro, Jesús
We have mapped the CO^12 J = 1-0 and J = 2-1 line emission in Markarian 86, one of the most metal-deficient blue compact dwarf galaxies so far detected in CO^12. The CO^12 emission is distributed in a horseshoe-like structure that follows the locus of the most recent star formation regions. The minimum in molecular line emission corresponds to the position of an older, massive nuclear starburst. The H_2 mass of the galaxy [in the range of (0.4-5) x 10^7 M_⨀] and its morphology have been compared with the predictions of hydrodynamic simulations of the evolution of the interstellar medium surrounding a nuclear starburst. These simulations suggest that the physical conditions in the gas swept out by the starburst could have led to the formation of the ring of molecular gas reported here. This result provides an attractive scenario for explaining the propagation (in a galactic scale) of the star formation in dwarf galaxies.
Specific star formation rate profiles in nearby spiral galaxies: Quantifying the inside-out formation of disks
(Astrophysical journal, 2007) Muñoz Mateos, J. C.; Gil de Paz, Armando; Boissier, S.; Zamorano Calvo, Jaime; Jarrett, T.; Gallego Maestro, Jesús; Madore, B. F.
We present specific star formation rate (sSFR) radial profiles for a sample of 161 relatively face-on spiral galaxies from the GALEX Atlas of NearbyGalaxies. The sSFR profiles are derived from GALEX and 2MASS (FUV-K) color profiles after a proper SFR calibration of the UV luminosity and K-band mass-to-light ratio are adopted. The (FUV-K) profiles were first corrected for foreground Galactic extinction and later for internal extinction using the ratio of the total-infrared (TIR) to FUV emission. For those objects where TIR-to-FUV ratio radial profiles were not available, the (FUV-NUV) color profiles were used as a measure of the UV slope. The sSFR radial gradients derived from these profiles allow us to quantify the inside-out scenario for the growth of spiral disks for the first time in the local universe. We find a large dispersion in the slope of the sSFR profiles with a slightly positive mean value, which implies a moderate inside-out disk formation. There is also a strong dependency of the value of this slope on the luminosity and size of the disks, with large systems showing a uniform, slightly positive slope in almost all cases and low-luminosity small disks showing a large dispersion with both positive and negative large values. While a majority of the galaxies can be interpreted as forming stars gradually either from inside out or from outside in, a few disks require episodes of enhanced recent growth with scale lengths of the SFR (or gas infall) being significantly larger at present than in the past. We do not find any clear dependence of the sSFR gradient on the environment (local galaxy density or presence of close neighbors).
Mapping the star formation history of Mrk 86 II. Stellar populations and global interpretation
(Astronomy and astrophysics, 2000) Gil de Paz, Armando; Zamorano Calvo, Jaime; Gallego Maestro, Jesús
In this paper, continuation of Gil de Pat et al. (Paper I), we derive the main properties of the stellar populations in the Blue Compact Dwarf galaxy Mrk 86. Ages, stellar masses, metallicites and burst strengths have been obtained using the combination of Monte Carlo simulations, a maximum likelihood estimator and Cluster and Principal Component Analysis. The three stellar populations detected show well defined properties. We have studied the underlying stellar population, which shows an age between 5-13 Gyr and no significant color gradients. The intermediate aged (30 Myr old) central starburst show a very low dust extinction with high burst strength and high stellar mass content (∼9x10^6 M_⨀). Finally, the properties of 46 low-metallicity (∼1/10Z_⨀) star-forming regions were also studied. The properties derived suggest that the most recent star-forming activity in Mrk 86 was triggered by the evolution of a superbubble originated at the central starburst by the energy deposition of stellar winds and supernova explosions. This superbubble produced the blowout of a fraction of the interstellar medium at distances of about 1 kpc with high gas surface densities, leading to the activation of the star formation. Finally, different mechanisms for the star formation triggering in this massive central starburst are studied, including the merging with a low mass companion and the interaction with UGC 4278. We have assumed a distance to Mrk 86 of 6.9 Mpc.
Mapping the star formation history of Mrk 86 - I. Data and models
(Astronomy & astrophysics supplement series, 2000) Gil de Paz, Armando; Zamorano Calvo, Jaime; Gallego Maestro, Jesús; Domínguez, F. de B.
We have obtained optical (BVR, [O III]ƛ 5007 Å and H_α), near infrared (JHK) imaging and long-slit optical spectroscopy for the Blue Compact Dwarf galaxy Mrk 86 (NGC 2537). In this paper, the first of two, we present optical-near-infrared colors and emission-line fluxes for the currently star-forming regions, intermediate aged starburst and underlying stellar population. We also describe the evolutionary synthesis models used in Paper II. The R and H_α luminosity distributions of the galaxy star-forming regions show maxima at M-R = -9.5^m and L_H_α = 10^37.3 ergs^-l. The underlying stellar population shows an exponential surface brigthness profile with central value, μ_E,0 = 21.5 mag arcsec^-2, and scale, α=0.88 kpc, both measured in the R-band image. In the galaxy outer regions, dominated by this component, no significant color gradients are observed. Finally, a complete set of evolutionary synthesis models have been developed, covering a wide range in metallicity, 1/50 Z_⨀< Z < 2 Z_⨀, and burst strength, 1-10^-4. These models include nebular continuum and recombination and forbidden-line emission.
Optical photometry of the UCM lists I and II - I. The data
(Astronomy & astrophysics supplement series, 2000) Pérez González, Pablo Guillermo; Zamorano Calvo, Jaime; Gallego Maestro, Jesús; Gil de Paz, Armando
We present Johnson B CCD photometry for the whole sample of galaxies of the Universidad Complutense de Madrid (UCM) Survey Lists I and II. They constitute a well-defined and complete sample of galaxies in the Local Universe with active star formation. The data refer to 191 SO to Irr galaxies at an averaged redshift of 0.027, and complement the already published Gunn r, J and K photometries. In this paper the observational and reduction features are discussed in detail, and the new colour information is combined to search for clues on thee properties of the galaxies, mainly by comparing our sample with other surveys.
Luminosity and stellar mass functions of local star-forming galaxies
(Astrophysical journal, 2003) Pérez González, Pablo Guillermo; Gallego Maestro, Jesús; Zamorano Calvo, Jaime; Alonso Herrero, A.; Gil de Paz, Armando; Aragón Salamanca, A.
We present the optical and near-infrared luminosity and mass functions of the local star-forming galaxies in the Universidad Complutense de Madrid (UCM) Survey. A bivariate method that explicitly deals with the Hα selection of the survey is used when estimating these functions. Total stellar masses have been calculated on a galaxy-by-galaxy basis taking into account differences in star formation histories. The main difference between the luminosity distributions of the UCM sample and the luminosity functions of the local galaxy population is a lower normalization (φ *), indicating a lower global volume density of UCM galaxies. The typical near-infrared luminosity (L*) of local star-forming galaxies is fainter than that of normal galaxies. This is a direct consequence of the lower stellar masses of our objects. However, at optical wavelengths (B and r), the luminosity enhancement arising from the young stars leads to M* values that are similar to those of normal galaxies. The fraction of the total optical and near-infrared luminosity density in the local universe associated with star-forming galaxies is 10%-20%. Fitting the total stellar mass function using a Schechter parameterization, we obtain α = -1.15 ± 0.15, log M* = 10.82 ± 0.17 M_☉, and log φ * = -3.04 ± 0.20 Mpc^-3. This gives an integrated total stellar mass density of 10^7.83±0.07 M_☉ Mpc-3 in local star-forming galaxies (H_0 = 70 km s^-1 Mpc^-1, Ω_M = 0.3, and Λ = 0.7). The volume-averaged burst strength of the UCM galaxies is b = 0.04 ± 0.01, defined as the ratio of the mass density of stars formed in recent bursts (with an age of <10 Myr) to the total stellar mass density in UCM galaxies. Finally, we derive that in the local universe, 13% ± 3% of the total baryon mass density in the form of stars is associated with star-forming galaxies.
Radial distribution of stars, gas, and dust in sings galaxies. II. Derived dust properties
(Astrophysical journal, 2009) Muñoz Mateos, J. C.; Gil de Paz, Armando; Boissier, S.; Zamorano Calvo, Jaime; Dale, D. A.; Pérez González, Pablo Guillermo; Gallego Maestro, Jesús; Madore, B. F.; Bendo, G.; Thornley, M. D.; Draine, B. T.; Boselli, A.; Buat, V.; Calzetti, D.; Moustakas, J.; Kennicutt, R. C. Jr.
We present a detailed analysis of the radial distribution of dust properties in the SINGS sample, performed on a set of ultraviolet (UV), infrared (IR), and Hi surface brightness profiles, combined with published molecular gas profiles and metallicity gradients. The internal extinction, derived from the total-IR (TIR)-to-far-UV (FUV) luminosity ratio, decreases with radius, and is larger in Sb-Sbc galaxies. The TIR-to-FUV ratio correlates with the UV spectral slope β, following a sequence shifted to redder UV colors with respect to that of starbursts. The star formation history (SFH) is identified as the main driver of this departure. Both L_TIR)/L_FUV and β correlate well with metallicity, especially in moderately face-on galaxies. The relation shifts to redder colors with increased scatter in more edge-on objects. By applying physical dust models to our radial spectral energy distributions, we have derived radial profiles of the total dust mass surface density, the fraction of the total dust mass contributed by polycyclic aromatic hydrocarbons (PAHs), and the intensity of the radiation field heating the grains. The dust profiles are exponential, their radial scale length being constant from Sb to Sd galaxies (only ~ 10% larger than the stellar scale length). Many S0/a-Sab galaxies have central depressions in their dust radial distributions. The PAH abundance increases with metallicity for 12 + log(O/H) < 9, and at larger metallicities the trend flattens and even reverses, with the SFH being a plausible underlying driver for this behavior. The dust-to-gas ratio is also well correlated with metallicity and therefore decreases with galactocentric radius. Although most of the total emitted IR power (especially in the outer regions of disks) is contributed by dust grains heated by diffuse starlight with a similar intensity as the local Milky Way radiation field, a small amount of the dust mass (~ 1%) is required to be exposed to very intense starlight in order to reproduce the observed fluxes at 24 μ m, accounting for ~ 10% of the total integrated IR power.
Star Formation Rate estimators: [O II]λ3727 vs. Hα for local star-forming galaxies
(Star formation through time: A conference to honour Roberto J. Terlevich, 2003) Aragón Salamanca, A.; Alonso Herrero, A.; Gallego Maestro, Jesús; García Dabó, C. E.; Pérez González, Pablo Guillermo; Zamorano Calvo, Jaime; Gil de Paz, Armando
The [O ii]λ3727 emission line is frequently used as an indicator of the star formation rate (SFR) despite its complex dependence on metallicity and excitation conditions. We have analysed the properties of the [O II] and Hα emission lines for a complete sample of local Hα-selected galaxies, the Universidad Complutense de Madrid (UCM) survey. We find a large scatter in the [O II]/Hα line ratios, although the scatter in the extinction-corrected [O II]^0/Hα^0 ratio is considerably smaller. We also find that the [O II]/Hα ratios are reasonably well correlated with the absolute B- and K-band magnitudes and with EW([O II]). However, the extinction-corrected [O II]^0/Hα^0 ratio is largely independent of these quantities, indicating that extinction is the main driver of the correlations. These correlations allow us to statistically predict-with varying degrees of accuracy-the observed and extinction-corrected Hα fluxes from the observed [O II] flux using the information contained in EW([O II]) and/or the absolute magnitudes, but extreme caution is needed to make sure that the sample selection effects are correctly taken into account.