28 research outputs found

    The complex star cluster system of NGC 1316 (Fornax A)

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    This paper presents Gemini-gri' high-quality photometry for cluster candidates in the field of NGC 1316 (Fornax A) as part of a study that also includes GMOS spectroscopy. A preliminary discussion of the photometric data indicates the presence of four stellar cluster populations with distinctive features in terms of age, chemical abundance and spatial distribution. Two of them seem to be the usually old (metal poor and metal rich) populations typically found in elliptical galaxies. In turn, an intermediate-age (5 Gyr) globular cluster population is the dominant component of the sample (as reported by previous papers). We also find a younger cluster population with a tentative age of ≈ 1 Gyr.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

    The complex star cluster system of NGC 1316 (Fornax A)

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    This paper presents Gemini-gri' high-quality photometry for cluster candidates in the field of NGC 1316 (Fornax A) as part of a study that also includes GMOS spectroscopy. A preliminary discussion of the photometric data indicates the presence of four stellar cluster populations with distinctive features in terms of age, chemical abundance and spatial distribution. Two of them seem to be the usually old (metal poor and metal rich) populations typically found in elliptical galaxies. In turn, an intermediate-age (5 Gyr) globular cluster population is the dominant component of the sample (as reported by previous papers). We also find a younger cluster population with a tentative age of ≈ 1 Gyr.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

    Deep MOS Spectroscopy of NGC1316 Globular Clusters

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    The giant elliptical galaxy NGC1316 is the brightest galaxy in the Fornax cluster, and displays a number of morphological features that might be interpreted as an intermediate age merger remanent ( 3 Gyr). Based on the idea that globular clusters systems (GCS) constitute genuine tracers of the formation and evolution of their host galaxies, we conducted a spectroscopic study of approximately 40 globular clusters (GCs) candidates associated with this interesting galaxy. We determined ages, metallicities, and a-element abundances for each GC present in the sample, through the measurement of different Lick indices and their subsequent comparison with simple stellar populations models (SSPs).Facultad de Ciencias Astronómicas y Geofísica

    The Southern Photometric Local Universe Survey (S-PLUS): improved SEDs, morphologies, and redshifts with 12 optical filters

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    The Southern Photometric Local Universe Survey (S-PLUS) is imaging ∼9300 deg² of the celestial sphere in 12 optical bands using a dedicated 0.8 m robotic telescope, the T80-South, at the Cerro Tololo Inter-american Observatory, Chile. The telescope is equipped with a 9.2k × 9.2k e2v detector with 10 μm pixels, resulting in a field of view of 2 deg² with a plate scale of 0.55 arcsec pixel⁻¹. The survey consists of four main subfields, which include two non-contiguous fields at high Galactic latitudes (|b| > 30°, 8000 deg²) and two areas of the Galactic Disc and Bulge (for an additional 1300 deg²). S-PLUS uses the Javalambre 12-band magnitude system, which includes the 5 ugriz broad-band filters and 7 narrow-band filters centred on prominent stellar spectral features: the Balmer jump/[OII], Ca H + K, H δ, G band, Mg b triplet, H α, and the Ca triplet. S-PLUS delivers accurate photometric redshifts (δz/(1 + z) = 0.02 or better) for galaxies with r < 19.7 AB mag and z < 0.4, thus producing a 3D map of the local Universe over a volume of more than 1(Gpc/h)³. The final S-PLUS catalogue will also enable the study of star formation and stellar populations in and around the Milky Way and nearby galaxies, as well as searches for quasars, variable sources, and low-metallicity stars. In this paper we introduce the main characteristics of the survey, illustrated with science verification data highlighting the unique capabilities of S-PLUS. We also present the first public data release of ∼336 deg² of the Stripe 82 area, in 12 bands, to a limiting magnitude of r = 21, available at datalab.noao.edu/splus.Instituto de Astrofísica de La Plat

    Young globular clusters in NGC1316

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    We present multi-object spectroscopy of the inner zone of the globular cluster (GC) system associated with the intermediate-age merger remnant NGC1316. Using the multi-object mode of the GMOS camera, we obtained spectra for 35 GCs. We find pieces of evidence that the innermost GCs of NGC1316 rotate almost perpendicular to the stellar component of the galaxy. In a second stage, we determined ages, metallicities, and α-element abundances for each GC present in the sample, through the measurement of different Lick/IDS indices and their comparison with simple stellar populationmodels.We confirmed the existence of multiple GC populations associated with NGC1316, where the presence of a dominant subpopulation of very young GCs, with an average age of 2.1 Gyr, metallicities between -0.5 < [Z/H] < 0.5 dex, and α-element abundances in the range -0.2 < [α/Fe] < 0.3 dex, stands out. Several objects in our sample present subsolar values of [α/Fe] and a large spread of [Z/H] and ages. Some of these objects could actually be stripped nuclei, possibly accreted duringminor merger events. Finally, the results have been analysed with the aim of describing the different episodes of star formation and thus provide a more complete picture about the evolutionary history of the galaxy. We conclude that these pieces of evidence could indicate that this galaxy has cannibalized one or more gas-rich galaxies, where the last fusion event occurred about 2 Gyr ago.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

    Young globular clusters in NGC1316

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    We present multi-object spectroscopy of the inner zone of the globular cluster (GC) system associated with the intermediate-age merger remnant NGC1316. Using the multi-object mode of the GMOS camera, we obtained spectra for 35 GCs. We find pieces of evidence that the innermost GCs of NGC1316 rotate almost perpendicular to the stellar component of the galaxy. In a second stage, we determined ages, metallicities, and α-element abundances for each GC present in the sample, through the measurement of different Lick/IDS indices and their comparison with simple stellar populationmodels.We confirmed the existence of multiple GC populations associated with NGC1316, where the presence of a dominant subpopulation of very young GCs, with an average age of 2.1 Gyr, metallicities between -0.5 < [Z/H] < 0.5 dex, and α-element abundances in the range -0.2 < [α/Fe] < 0.3 dex, stands out. Several objects in our sample present subsolar values of [α/Fe] and a large spread of [Z/H] and ages. Some of these objects could actually be stripped nuclei, possibly accreted duringminor merger events. Finally, the results have been analysed with the aim of describing the different episodes of star formation and thus provide a more complete picture about the evolutionary history of the galaxy. We conclude that these pieces of evidence could indicate that this galaxy has cannibalized one or more gas-rich galaxies, where the last fusion event occurred about 2 Gyr ago.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

    Star formation history of stellar systems in NGC 1316

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    Galaxy mergers are often considered in the literature as ideal places to study diverse starburststriggered during the merger events. In that sense, the intermediate-age merger remnant NGC 1316 constitutes a perfect case to study complex large-scale star formation events in the Local Universe. In a series of previous works we confirmed the existence of a complex globular cluster (GC) system associated with NGC 1316, which is dominated by the presence of an unusual young (≈ 2.1 Gyr) and metal-rich subpopulation (−0.5 < [Z/H] <0.5 dex), possibly created during the last merger event. In this work we used high-quality spectroscopic data from Gemini/GMOS to present an analysis of the the star formation history of three GCs associated to this galaxy. Although recent works show the presence of multiple stellar populations in old GCs in the Milky Way and nearby galaxies, this project constitutes one of the first studies to show multiple stellar populations in young extragalacticGCs.Fil: Sesto, Leandro Alberto. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Escudero, Carlos Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Faifer, Favio Raúl. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Reynaldi, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Smith Castelli, Analia Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Barbosa, C. E.. No especifíca;62º Reunión Anual de la Asociación Argentina de AstronomíaArgentinaAsociación Argentina de Astronomí

    Deep MOS Spectroscopy of NGC1316 Globular Clusters

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    The giant elliptical galaxy NGC1316 is the brightest galaxy in the Fornax cluster, and displays a number of morphological features that might be interpreted as an intermediate age merger remanent ( 3 Gyr). Based on the idea that globular clusters systems (GCS) constitute genuine tracers of the formation and evolution of their host galaxies, we conducted a spectroscopic study of approximately 40 globular clusters (GCs) candidates associated with this interesting galaxy. We determined ages, metallicities, and a-element abundances for each GC present in the sample, through the measurement of different Lick indices and their subsequent comparison with simple stellar populations models (SSPs).Facultad de Ciencias Astronómicas y Geofísica

    Exploring the inner region of NGC 1316 through CO ALMA data

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    The merger remnant NGC 1316 (Fornax A) is the brightest galaxy in the Fornax cluster, and it is thethird nearest radio-bright galaxy (D = 20.8 ± 0.5 Mpc) hosting an Active Galactic Nuclei. Due to the complexityof this source, on a variety of scales and components, it was observed at different wavelengths. Deep opticalimages revealed complex structures such as ripples and loops in its outer regions, while far-infrared observationsshow prominent dust extinction in its inner part. The dust is found in diverse structures that include a northwest shell, a south-east blob, an extended component to the south-west, and dust patches among them. Someof these features are well traced by CO as well. The presence of a bent nuclear jet was reported in previousworks, after radio continuum observations, suggesting an interaction between the jet and the interstellar mediumof the galaxy. NGC 1316 is a remarkable object because it harbours a notable subpopulation of young globularclusters. To better understand the history and the physical processes that are currently taking place in the innerregion of NGC 1316, we started to gather the public data at various spectral ranges, from instruments such asALMA, VLA, Chandra and HST. In this poster, we will focus on the available CO(J=2-1) ALMA data, and theinformation that could be retrieved from themFil: Saponara, Juliana. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Reynaldi, María Victoria. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Smith Castelli, Analia Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Faifer, Favio Raúl. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Benaglia, Paula. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Sesto, Leandro Alberto. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Escudero, Carlos Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina62° Reunión Anual de la Asociación Argentina de AstronomíaRosarioArgentinaUniversidad Nacional de RosarioComplejo Astronómico Municipal Galileo Galile

    Globular clusters: DNA of early-type galaxies?

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    This paper explores if the mean properties of early-type galaxies (ETGs) can be reconstructed from 'genetic' information stored in their globular clusters (GCs; i.e. in their chemical abundances, spatial distributions and ages). This approach implies that the formation of each globular occurs in very massive stellar environments, as suggested by some models that aim at explaining the presence of multipopulations in these systems. The assumption that the relative number of GCs to diffuse stellar mass depends exponentially on chemical abundance, [Z/H], and the presence of two dominant GC subpopulations (blue and red), allows the mapping of low-metallicity haloes and of higher metallicity (and more heterogeneous) bulges. In particular, the masses of the low-metallicity haloes seem to scale up with dark matter mass through a constant. We also find a dependence of the GC formation efficiency with the mean projected stellar mass density of the galaxies within their effective radii. The analysis is based on a selected subsample of galaxies observed within the ACS Virgo Cluster Survey of the Hubble Space Telescope. These systems were grouped, according to their absolute magnitudes, in order to define composite fiducial galaxies and look for a quantitative connection with their (also composite) GCs systems. The results strengthen the idea that GCs are good quantitative tracers of both baryonic and dark matter in ETGs.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat
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