Person: Zamorano Calvo, Jaime
Loading...
First Name
Jaime
Last Name
Zamorano Calvo
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Físicas
Department
Física de la Tierra y Astrofísica
Area
Astronomía y Astrofísica
Identifiers
10 results
Search Results
Now showing 1 - 10 of 10
Item The [O II] λ3727 luminosity function of the local universe(Astrophysical journal, 2002) Gallego Maestro, Jesús; García Dabó, C. E.; Zamorano Calvo, Jaime; Aragón Salamanca, A.; Rego Fernández, ManuelThe measurement of the star formation rate density of the universe is of prime importance in understanding the formation and evolution of galaxies. The [O ii] λ3727 emission-line flux, easy to measure up to z ≈ 1.4 within deep redshift surveys in the optical and up to in the near-infrared, offers a reliable means of z ≈ 5.4 characterizing the star formation properties of high-z objects. In order to provide the high-z studies with a local reference, we have measured total [O ii] λ3727 fluxes for the well-analyzed local sample of star-forming galaxies from the Universidad Complutense de Madrid Survey. These data are used to derive the [O ii] λ3727 luminosity function for local star-forming galaxies. When compared with similar luminosity densities published for redshift up to, the overall evolution already observed in the star formation activity of the universe is confirmed.Item Properties of Hα-selected star-forming galaxies from z ∼ 0.8 to now(II International GTC Workshop: Science with GTC 1st-Light Instruments and the LMT, Gallego Maestro, Jesús y Zamorano Calvo, Jaime y Pascual Ramírez, Sergio y Villar, V. (2005) Emission-line galaxy surveys with GTC: The Hα Universe. In II International GTC Workshop: Science with GTC 1st-Light Instruments and the LMT, 2005) Pascual Ramírez, Sergio; Villar, V.; Gallego Maestro, Jesús; Zamorano Calvo, Jaime; Pelló, R.; Díaz-Guerra Viejo, Carlos; Aragón Salamanca, A.We present a long-term project to study the characteristics and evolution of current star-forming galaxies at different redshifts. Our results support the idea that the higher Star Formation Density measured at redshift z=0.24 is due to an increase of the density of bursting galaxies and not to an intrinsic change on overall galaxy properties.Item Hα emitting galaxies and the star formation rate density at z ≃ 0.24(Astronomy and astrophysics, 2001) Pascual, S.; Gallego Maestro, Jesús; Aragón Salamanca, A.; Zamorano Calvo, JaimeWe have carried out a survey searching for Hα emitting galaxies at z ≃ 0.24 using a narrow band filter tuned with the redshifted line. The total sky area covered was 0.19 square degrees within the redshift range 0.228 to 0.255 in a set of four fields in the ELAIS-N1 zone. This corresponds to a volume of 9.8 x 10^3 Mpc^3 and a look-back time of 3.6 Gyr when H_0 = 50 km s^-1 Mpc^-1 and q_0 = 0.5 are assumed. A total of 52 objects are selected as candidates for a broad band limiting magnitude of I ~ 22.9, plus 16 detected only in the narrow band image for a narrow band limiting magnitude for object detection of 21.0. The threshold detection corresponds to about 20 Å equivalent width with an uncertainty of ~± 10 Å. Point-like objects (15) were excluded from our analysis using CLASS STAR parameter from SExtractor. The contamination from other emission lines such as [O II] λ 3727, H _ β and [O III] λ λ 4959, 5007 at redshifts 1.2, 0.66 and 0.61 respectively is estimated, and found to be negligible at the flux limits of our sample. We find an extinction-corrected H_ α luminosity density of (5.4 ± 1.1) x 10^39 erg s^-1 Mpc^-3. This uncertainty takes into account the photometric and Poissonian errors only. Assuming a constant relation between the H_α luminosity and star formation rate, the SFR density in the covered volume is (0.043 ± 0.009) M_⨀ yr^-1 Mpc^-3. This translates to (0.037 ± 0.009) M¬_⨀ yr^-1 Mpc^-3 when the total density is corrected for the AGN contribution as estimated in the local Universe. This value is a factor ~4 higher than the local SFR density. This result needs to be confirmed by future spectroscopic follow-up observations.Item Star formation properties of Universidad Complutense de Madrid survey galaxies(Monthly notices of the Royal Astronomical Society, 2000) Gil de Paz, Armando; Aragón Salamanca, A.; Gallego Maestro, Jesús; Alonso Herrero, A.; Zamorano Calvo, Jaime; Kauffmann, G.We present new near-infrared J and K imaging data for 67 galaxies from the Universidad Complutense de Madrid (UCM) survey used in the determination of the SFR density of the local Universe by Gallego et al. This is a sample of local star-forming galaxies with redshift lower than 0.045, and they constitute a representative subsample of the galaxies in the complete UCM survey. From the new data, complemented with our own Gunn−r images and long-slit optical spectroscopy, we have measured integrated K-band luminosities, r−J and J−K colours, and Hα luminosities and equivalent widths. Using a maximum likelihood estimator and a complete set of evolutionary synthesis models, these observations allow us to estimate the strength of the current (or most recent) burst of star formation, its age, the star formation rate and the total stellar mass of the galaxies. An average galaxy in the sample has a stellar mass of 5×10^10 M_⊙ and is undergoing (or has recently completed) a burst of star formation involving about 2 per cent of its total stellar mass. We identify two separate classes of star-forming galaxies in the UCM sample: low-luminosity, high-excitation galaxies (HII-like) and relatively luminous spiral galaxies (starburst disk−like). The former show higher specific star formation rates (SFRs per unit mass) and burst strengths, and lower stellar masses than the latter. With regard to their specific star formation rates, the UCM galaxies are intermediate objects between normal quiescent spirals and the most extreme H II galaxies.Item 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.Item 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, ArmandoThe [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.Item The [O II] ƛ3727 luminosity function of the local universe(Astrophysical journal, 2002) Gallego Maestro, Jesús; García Dabó, C. E.; Zamorano Calvo, Jaime; Aragón Salamanca, A.; Rego Fernández, ManuelThe measurement of the star formation rate density of the universe is of prime importance in understanding the formation and evolution of galaxies. The [O II] ƛ3727 emission-line flux, easy to measure up to z ≈ 1.4 within deep redshift surveys in the optical and up to z ≈ 5/4 in the near-infrared, offers a reliable means of characterizing the star formation properties of high-z objects. In order to provide the high-z studies with a local reference, we have measured total [O II] ƛ3727 fluxes for the well-analyzed local sample of star-forming galaxies from the Universidad Complutense de Madrid Survey. These data are used to derive the [O II] ƛ3727 luminosity function for local star-forming galaxies. When compared with similar luminosity densities published for redshift up to z ≈ 1, the overall evolution already observed in the star formation activity of the universe is confirmed.Item Spatial analysis of the Hα emission in the local star-forming UCM galaxies(Astrophysical journal, 2003) Pérez González, Pablo Guillermo; Zamorano Calvo, Jaime; Gallego Maestro, Jesús; Aragón Salamanca, A.; Gil de Paz, ArmandoWe present a photometric study of the Halpha emission in the Universidad Complutense de Madrid (UCM) Survey galaxies. This work complements our previously published spectroscopic data. We study the location of the star-forming knots, their intensity and concentration, and the relationship of these properties with those of the host galaxy. We also estimate that the amount of Halpha emission that arises from the diffuse ionized gas is about 15% - 30% of the total Hα flux for a typical UCM galaxy. This percentage seems to be independent of the Hubble type. Conversely, we find that an "average'' UCM galaxy harbors a star formation event with 30% of its Hα luminosity arising from a nuclear component. The implications of these results for higher redshift studies are discussed, including the effects of galaxy size and the depth of the observations. A correlation between the star formation rate and the Balmer decrement is observed, but such correlation breaks down for large values of the extinction. Finally, we recalculate the Hα luminosity function and star formation rate density of the local universe using the new imaging data. Our results point out that, on average, spectroscopic observations detected about one-third of the total emission-line flux of a typical UCM galaxy. The new values obtained for the Halpha luminosity density and the star formation rate density of the local universe are 10^39.3±0.2 ergs s^-1 Mpc^-3 and ρ(SFR) = 0.016_-0.004^+0.007) M_⨀ yr-1 Mpc^-3 (H_0 = 50 km s^-1) Mpc^-1, Ω_M) = 1.0, Λ = 0). The corresponding values for the "concordance cosmology (H_0 = 70 km s^-1 Mpc^-1, Ω_M) = 0.3, Λ = 0.7) are 10^39.5±0.2 ergs s^-1 Mpc-3) and ρ_SFR = 0.029_-0.005^+0.008 M_⨀ yr^-1 Mpc^-3.Item Stellar populations in local star-forming galaxies - II. Recent star formation properties and stellar masses(Monthly notices of the Royal Astronomical Society, 2003) Pérez González, Pablo Guillermo; Gil de Paz, Armando; Zamorano Calvo, Jaime; Gallego Maestro, Jesús; Alonso Herrero, A.; Aragón Salamanca, A.We present the integrated properties of the stellar populations in the Universidad Complutense de Madrid (UCM) Survey galaxies. Applying the techniques described in the first paper of this series, we derive ages, burst masses and metallicities of the newly formed stars in our sample galaxies. The population of young stars is responsible for the Halpha emission used to detect the objects in the UCM Survey. We also infer total stellar masses and star formation rates in a consistent way taking into account the evolutionary history of each galaxy. We find that an average UCM galaxy has a total stellar mass of ∼10^10 M_⨀, of which about 5 per cent was formed in an instantaneous burst that occurred about 5 Myr ago, and subsolar metallicity. Less than 10 per cent of the sample shows massive starbursts involving more than half of the total mass of the galaxy. Several correlations are found among the derived properties. The burst strength is correlated with the extinction and with the integrated optical colours for galaxies with low obscuration. The current star formation rate is correlated with the gas content. A stellar mass-metallicity relation is also found. Our analysis indicates that the UCM Survey galaxies span a broad range in properties between those of galaxies completely dominated by current/recent star formation and those of normal quiescent spirals. We also find evidence indicating that star formation in the local Universe is dominated by galaxies considerably less massive than L^*.Item Multiwavelength study of star-forming galaxies in the local Universe(II International GTC Workshop: Science with GTC 1st-Light Instruments and the LMT, 2005) Zamorano Calvo, Jaime; Díaz-Guerra Viejo, Carlos; Gallego Maestro, Jesús; Pérez González, Pablo Guillermo; Gil de Paz, Armando; Pascual, S.; Villar, V.; Alonso Herrero, A.; Aragón Salamanca, A.We have studied in detail the properties of local active star-forming galaxies from the UCM survey, and in particular their star-formation histories. We have quantified the relative importance of the current episode of star formation in comparison to the underlying older stellar populations. We have also determined the total stellar mass function and burst mass function for the UCM sample using the M/L calculated for each galaxy. Integrating this mass function we obtained the contribution of the star-forming galaxies to the total stellar mass density of the local Universe.