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30 results on '"Aguerri, A. L."'

1. Calibration at elevation of the WEAVE fibre positioner

Author

Hughes, Sarah, Dalton, Gavin, Dee, Kevin, Abrams, Don Carlos, Middleton, Kevin, Lewis, Ian, Terrett, David, Aguerri, Alfonso L., Balcells, Marc, Bishop, Georgia, Bonifacio, Piercarlo, Carrasco, Esperanza, Trager, Scott, and Vallenari, Antonella

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

WEAVE is the new wide-field spectroscopy facility for the prime focus of the William Herschel Telescope in La Palma, Spain. Its fibre positioner is essential for the accurate placement of the spectrograph's 960 fibre multiplex. We provide an overview of the recent maintenance, flexure modifications, and calibration measurements conducted at the observatory prior to the final top-end assembly. This work ensures that we have a complete understanding of the positioner's behaviour as it changes orientation during observations. All fibre systems have been inspected and repaired, and the tumbler structure contains new clamps to stiffen both the internal beam and the retractor support disk onto which the field plates attach. We present the updated metrology procedures and results that will be verified on-sky., Comment: 16 pages, 16 figures

Published
2022
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2. Photometric Signature of Ultra-Harmonic Resonances in Barred Galaxies

Author

Krishnarao, Dhanesh, Pace, Zachary J., D'Onghia, Elena, Aguerri, Alfonso L., McClure, Rachel L., Peterken, Thomas, Fernandez-Trincado, Jose G., Merrifield, Michael, Masters, Karen L., Garma-Oehmichen, Luis, Boardman, Nicholas Fraser, Bershady, Matthew, Drory, Niv, and Lane, Richard R.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

Bars may induce morphological features, such as rings, through their resonances. Previous studies suggested that the presence of 'dark-gaps', or regions of a galaxy where the difference between the surface brightness along the bar major axis and along the bar minor axis are maximal, can be attributed to the location of bar corotation. Here, using GALAKOS, a high-resolution N-body simulation of a barred galaxy, we test this photometric method's ability to identify the bar corotation resonance. Contrary to previous work, our results indicate that 'dark-gaps' are a clear sign of the location of the 4:1 ultra-harmonic resonance instead of bar corotation. Measurements of the bar corotation can indirectly be inferred using kinematic information, e.g., by measuring the shape of the rotation curve. We demonstrate our concept on a sample of 578 face-on barred galaxies with both imaging and integral field observations and find the sample likely consists primarily of fast bars., Comment: 16 pages, 14 figures, Accepted for publication in ApJ

Published
2022
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3. The Mice at play in the CALIFA survey: A case study of a gas-rich major merger between first passage and coalescence

Author

Wild, Vivienne, Rosales-Ortega, Fabian, Falcon-Barroso, Jesus, Garcia-Benito, Ruben, Gallazzi, Anna, Delgado, Rosa M. Gonzalez, Bekeraite, Simona, Pasquali, Anna, Johansson, Peter H., Lorenzo, Begona Garcia, van de Ven, Glenn, Pawlik, Milena, Perez, Enrique, Monreal-Ibero, Ana, Lyubenova, Mariya, Fernandes, Roberto Cid, Mendez-Abreu, Jairo, Barrera-Ballesteros, Jorge, Kehrig, Carolina, Iglesias-Paramo, Jorge, Bomans, Dominik J., Marquez, Isabel, Johnson, Benjamin D., Kennicutt, Robert C., Husemann, Bernd, Mast, Damian, Sanchez, Sebastian F., Walcher, C. Jakob, Alves, Joao, Aguerri, Alfonso L., Herrero, Almudena Alonso, Bland-Hawthorn, Joss, Catalan-Torrecilla, Cristina, Florido, Estrella, Gomes, Jean Michel, Jahnke, Knud, Lopez-Sanchez, A. R., de Lorenzo-Caceres, Adriana, Marino, Raffaella A., Marmol-Queralto, Esther, Olden, Patrick, del Olmo, Ascension, Papaderos, Polychronis, Quirrenbach, Andreas, Vilchez, Jose M., and Ziegler, Bodo

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

We present optical integral field spectroscopy (IFS) observations of the Mice, a major merger between two massive (>10^11Msol) gas-rich spirals NGC4676A and B, observed between first passage and final coalescence. The spectra provide stellar and gas kinematics, ionised gas properties and stellar population diagnostics, over the full optical extent of both galaxies. The Mice provide a perfect case study highlighting the importance of IFS data for improving our understanding of local galaxies. The impact of first passage on the kinematics of the stars and gas has been significant, with strong bars likely induced in both galaxies. The barred spiral NGC4676B exhibits a strong twist in both its stellar and ionised gas disk. On the other hand, the impact of the merger on the stellar populations has been minimal thus far: star formation induced by the recent close passage has not contributed significantly to the global star formation rate or stellar mass of the galaxies. Both galaxies show bicones of high ionisation gas extending along their minor axes. In NGC4676A the high gas velocity dispersion and Seyfert-like line ratios at large scaleheight indicate a powerful outflow. Fast shocks extend to ~6.6kpc above the disk plane. The measured ram pressure and mass outflow rate (~8-20Msol/yr) are similar to superwinds from local ULIRGs, although NGC4676A has only a moderate infrared luminosity of 3x10^10Lsol. Energy beyond that provided by the mechanical energy of the starburst appears to be required to drive the outflow. We compare the observations to mock kinematic and stellar population maps from a merger simulation. The models show little enhancement in star formation during and following first passage, in agreement with the observations. We highlight areas where IFS data could help further constrain the models., Comment: 23 pages, 13 figures, accepted to A&A. A version with a complete set of high resolution figures is available here: http://www-star.st-and.ac.uk/~vw8/resources/mice_v8_astroph.pdf

Published
2014
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4. The ALHAMBRA Survey: Bayesian Photometric Redshifts with 23 bands for 3 squared degrees

Author

Molino, A., Benítez, N., Moles, M., Fernández-Soto, A., Cristóbal-Hornillos, D., Ascaso, B., Jiménez-Teja, Y., Schoenell, W., Arnalte-Mur, P., Pović, M., Coe, D., López-Sanjuan, C., Díaz-García, L. A., Varela, J., Matute, I., Masegosa, J., Márquez, I., Perea, J., Del Olmo, A., Husillos, C., Alfaro, E., Aparicio-Villegas, T., Cerviño, M., Huertas-Company, M., Aguerri, A. L., Broadhurst, T., Cabrera-Caño, J., Cepa, J., Delgado, R. M. González, Infante, L., Martínez, V. J., Prada, F., and Quintana, J. M.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The ALHAMBRA (Advance Large Homogeneous Area Medium Band Redshift Astronomical) survey has observed 8 different regions of the sky, including sections of the COSMOS, DEEP2, ELAIS, GOODS-N, SDSS and Groth fields using a new photometric system with 20 contiguous ~ $300\AA$ filters covering the optical range, combining them with deep $JHKs$ imaging. The observations, carried out with the Calar Alto 3.5m telescope using the wide field (0.25 sq. deg FOV) optical camera LAICA and the NIR instrument Omega-2000, correspond to ~700hrs on-target science images. The photometric system was designed to maximize the effective depth of the survey in terms of accurate spectral-type and photo-zs estimation along with the capability of identification of relatively faint emission lines. Here we present multicolor photometry and photo-zs for ~438k galaxies, detected in synthetic F814W images, complete down to I~24.5 AB, taking into account realistic noise estimates, and correcting by PSF and aperture effects with the ColorPro software. The photometric ZP have been calibrated using stellar transformation equations and refined internally, using a new technique based on the highly robust photometric redshifts measured for emission line galaxies. We calculate photometric redshifts with the BPZ2 code, which includes new empirically calibrated templates and priors. Our photo-zs have a precision of $dz/(1+z_s)=1%$ for I<22.5 and 1.4% for 22.5=0.56 for I<22.5 AB and =0.86 for I<24.5 AB. The data presented here covers an effective area of 2.79 sq. deg, split into 14 strips of 58.5'x15.5' and represents ~32 hrs of on-target., Comment: The catalog data and a full resolution version of this paper is available at https://cloud.iaa.csic.es/alhambra/

Published
2013
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5. The HST/ACS Coma Cluster Survey. II. Data Description and Source Catalogs

Author

Hammer, Derek, Kleijn, Gijs Verdoes, Hoyos, Carlos, Brok, Mark den, Balcells, Marc, Ferguson, Henry C., Goudfrooij, Paul, Carter, David, Guzman, Rafael, Peletier, Reynier F., Smith, Russell J., Graham, Alister W., Trentham, Neil, Peng, Eric, Puzia, Thomas H., Lucey, John R., Jogee, Shardha, Aguerri, Alfonso L., Batcheldor, Dan, Bridges, Terry J., Davies, Jonathan I., del Burgo, Carlos, Erwin, Peter, Hornschemeier, Ann, Hudson, Michael J., Huxor, Avon, Jenkins, Leigh, Karick, Arna, Khosroshahi, Habib, Kourkchi, Ehsan, Komiyama, Yutaka, Lotz, Jennifer, Marzke, Ronald O., Marinova, Irina, Matkovic, Ana, Merritt, David, Miller, Bryan W., Miller, Neal A., Mobasher, Bahram, Mouhcine, Mustapha, Okamura, Sadanori, Percival, Sue, Phillipps, Steven, Poggianti, Bianca M., Price, James, Sharples, Ray M., Tully, R. Brent, and Valentijn, Edwin

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

The Coma cluster was the target of a HST-ACS Treasury program designed for deep imaging in the F475W and F814W passbands. Although our survey was interrupted by the ACS instrument failure in 2007, the partially completed survey still covers ~50% of the core high-density region in Coma. Observations were performed for 25 fields that extend over a wide range of cluster-centric radii (~1.75 Mpc) with a total coverage area of 274 arcmin^2. The majority of the fields are located near the core region of Coma (19/25 pointings) with six additional fields in the south-west region of the cluster. In this paper we present reprocessed images and SExtractor source catalogs for our survey fields, including a detailed description of the methodology used for object detection and photometry, the subtraction of bright galaxies to measure faint underlying objects, and the use of simulations to assess the photometric accuracy and completeness of our catalogs. We also use simulations to perform aperture corrections for the SExtractor Kron magnitudes based only on the measured source flux and half-light radius. We have performed photometry for ~73,000 unique objects; one-half of our detections are brighter than the 10-sigma point-source detection limit at F814W=25.8 mag (AB). The slight majority of objects (60%) are unresolved or only marginally resolved by ACS. We estimate that Coma members are 5-10% of all source detections, which consist of a large population of unresolved objects (primarily GCs but also UCDs) and a wide variety of extended galaxies from a cD galaxy to dwarf LSB galaxies. The red sequence of Coma member galaxies has a constant slope and dispersion across 9 magnitudes (-21

Published
2010
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6. The HST/ACS Coma Cluster Survey: I - Survey Objectives and Design

Author

Carter, David, Goudfrooij, Paul, Mobasher, Bahram, Ferguson, Henry C., Puzia, Thomas H., Aguerri, Alfonso L., Balcells, Marc, Batcheldor, Dan, Bridges, Terry J., Davies, Jonathan I., Erwin, Peter, Graham, Alister W., Guzmán, Rafael, Hammer, Derek, Hornschemeier, Ann, Hoyos, Carlos, Hudson, Michael J., Huxor, Avon, Jogee, Shardha, Komiyama, Yutaka, Lotz, Jennifer, Lucey, John R., Marzke, Ronald O., Merritt, David, Miller, Bryan W., Miller, Neal A., Mouhcine, Mustapha, Okamura, Sadanori, Peletier, Reynier F., Phillipps, Steven, Poggianti, Bianca M., Sharples, Ray M., Smith, Russell J., Trentham, Neil, Tully, R. Brent, Valentijn, Edwin, and Kleijn, Gijs Verdoes

Subjects
Astrophysics
Abstract

We describe the HST ACS Coma cluster Treasury survey, a deep two-passband imaging survey of one of the nearest rich clusters of galaxies, the Coma cluster (Abell 1656). The survey was designed to cover an area of 740 square arcmin in regions of different density of both galaxies and intergalactic medium within the cluster. The ACS failure of January 27th 2007 leaves the survey 28% complete, with 21 ACS pointings (230 square arcmin) complete, and partial data for a further 4 pointings (44 square arcmin). Predicted survey depth for 10 sigma detections for optimal photometry of point sources is g' = 27.6 in the F475W filter, and IC=26.8 mag in F814 (AB magnitudes). Initial simulations with artificially injected point sources show 90% recovered at magnitude limits of g' = 27.55 and IC = 26.65. For extended sources, the predicted 10 sigma limits for a 1 square arcsecond region are g' = 25.8 mag/sq. arcsec and IC = 25.0 mag/sq. arcsec. We highlight several motivating science goals of the survey, including study of the faint end of the cluster galaxy luminosity function, structural parameters of dwarf galaxies, stellar populations and their effect on colors and color gradients, evolution of morphological components in a dense environment, the nature of ultra compact dwarf galaxies, and globular cluster populations of cluster galaxies of a range of luminosities and types. This survey will also provide a local rich cluster benchmark for various well known global scaling relations and explore new relations pertaining to the nuclear properties of galaxies., Comment: 47 pages, 3 figures, 6 tables, accepted for publication in Astrophysical Journal supplement

Published
2008
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8. Calibration at elevation of the WEAVE fibre positioner

Author

Evans, Christopher J., Bryant, Julia J., Motohara, Kentaro, Hughes, Sarah, Dalton, Gavin, Dee, Kevin, Abrams, Don Carlos, Middleton, Kevin, Lewis, Ian, Terrett, David, Aguerri, Alfonso L., Balcells, Marc, Bishop, Georgia, Bonifacio, Piercarlo, Carrasco, Esperanza, Trager, Scott C., and Vallenari, Antonella

Published
2022
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10. MEGARA, the R=6000-20000 IFU and MOS of GTC

Author

Carrasco, E., Gil de Paz, A., Gallego, J., Iglesias-Páramo, J., Cedazo, R., García Vargas, M. L., Arrillaga, X., Avilés, J. L., Bouquin, A., Carbajo, J., Cardiel, Nicolás, Carrera, M. A., Castillo Morales, A., Castillo-Domínguez, E., Esteban San Román, S., Ferrusca, D., Gómez-Álvarez, P., Izazaga-Pérez, R., Lefort, B., López Orozco, J. A., Maldonado, M., Martínez Delgado, Ismael, Morales Durán, I., Mújica, E., Ortiz, R., Páez, G., Pascual, S., Pérez-Calpena, A., Picazo, P., Sánchez-Penim, A., Sánchez-Blanco, E., Tulloch, S., Velázquez, M., Vílchez Medina, José Manuel, Zamorano, J., Aguerri, A. L., Barrado y Navascués, David, Bertone, E., Cava, A., Catalán-Torrecilla, C., Cenarro, J., Chávez, M., Dullo, B. T., Eliche, C., García, Miriam, García-Rojas, J., Guichard, J., González-Delgado, R., Guzmán, R., Herrero, A., Huélamo, Nuria, Hughes, D. H., Jiménez-Vicente, J., Kehrig, C., Marino, R.A., Márquez, Isabel, Masegosa, Josefa, Mayya, D., Méndez-Abreu, J., Mollá, M., Muñoz-Tuñón, C., Peimbert, M., Pérez-González, Pablo G., Pérez Montero, Enrique, Roca-Fàbrega, S., Rodríguez, M., Rodríguez-Espinosa, J. M., Rodríguez-Merino, L., Rodríguez-Muñoz, L., González Delgado, Rosa M., Sánchez-Almeida, J., Sánchez Contreras, C., Sánchez-Blázquez, P., Sánchez, Sebastián F., Sarajedini, A., Silich, S., Simón-Díaz, S., Tenorio-Tagle, G., Terlevich, E., Terlevich, R., Torres-Peimbert, S., Trujillo, I., Tsamis, Y., Vega, O., Carrasco, E., Gil de Paz, A., Gallego, J., Iglesias-Páramo, J., Cedazo, R., García Vargas, M. L., Arrillaga, X., Avilés, J. L., Bouquin, A., Carbajo, J., Cardiel, Nicolás, Carrera, M. A., Castillo Morales, A., Castillo-Domínguez, E., Esteban San Román, S., Ferrusca, D., Gómez-Álvarez, P., Izazaga-Pérez, R., Lefort, B., López Orozco, J. A., Maldonado, M., Martínez Delgado, Ismael, Morales Durán, I., Mújica, E., Ortiz, R., Páez, G., Pascual, S., Pérez-Calpena, A., Picazo, P., Sánchez-Penim, A., Sánchez-Blanco, E., Tulloch, S., Velázquez, M., Vílchez Medina, José Manuel, Zamorano, J., Aguerri, A. L., Barrado y Navascués, David, Bertone, E., Cava, A., Catalán-Torrecilla, C., Cenarro, J., Chávez, M., Dullo, B. T., Eliche, C., García, Miriam, García-Rojas, J., Guichard, J., González-Delgado, R., Guzmán, R., Herrero, A., Huélamo, Nuria, Hughes, D. H., Jiménez-Vicente, J., Kehrig, C., Marino, R.A., Márquez, Isabel, Masegosa, Josefa, Mayya, D., Méndez-Abreu, J., Mollá, M., Muñoz-Tuñón, C., Peimbert, M., Pérez-González, Pablo G., Pérez Montero, Enrique, Roca-Fàbrega, S., Rodríguez, M., Rodríguez-Espinosa, J. M., Rodríguez-Merino, L., Rodríguez-Muñoz, L., González Delgado, Rosa M., Sánchez-Almeida, J., Sánchez Contreras, C., Sánchez-Blázquez, P., Sánchez, Sebastián F., Sarajedini, A., Silich, S., Simón-Díaz, S., Tenorio-Tagle, G., Terlevich, E., Terlevich, R., Torres-Peimbert, S., Trujillo, I., Tsamis, Y., and Vega, O.

Abstract

MEGARA is the new generation IFU and MOS optical spectrograph built for the 10.4m Gran Telescopio CANARIAS (GTC). The project was developed by a consortium led by UCM (Spain) that also includes INAOE (Mexico), IAA-CSIC (Spain) and UPM (Spain). The instrument arrived to GTC on March 28th 2017 and was successfully integrated and commissioned at the telescope from May to August 2017. During the on-sky commissioning we demonstrated that MEGARA is a powerful and robust instrument that provides on-sky intermediate-to-high spectral resolutions RFWHM ~ 6,000, 12,000 and 20,000 at an unprecedented efficiency for these resolving powers in both its IFU and MOS modes. The IFU covers 12.5 x 11.3 arcsec 2 while the MOS mode allows observing up to 92 objects in a region of 3.5 x 3.5 arcmin 2 . In this paper we describe the instrument main subsystems, including the Folded-Cassegrain unit, the fiber link, the spectrograph, the cryostat, the detector and the control subsystems, and its performance numbers obtained during commissioning where the fulfillment of the instrument requirements is demonstrated. © 2018 SPIE.

Published
2018

11. First scientific observations with MEGARA at GTC

Author

Gil de Paz, A., Carrasco, E., Gallego, J., Iglesias-Páramo, J., Cedazo, R., García-Vargas, M. L., Arrillaga, X., Avilés, J. L., Bouquin, A., Carbajo, J., Cardiel, Nicolás, Carrera, M. A., Castillo-Morales, A., Castillo-Domínguez, E., Esteban San Román, S., Ferrusca, D., Gómez-Álvarez, P., Izazaga-Pérez, R., Lefort, B., López-Orozco, J. A., Maldonado, M., Martínez-Delgado, I., Morales-Durán, I., Mújica, E., Páez, G., Pascual, S., Pérez-Calpena, A., Picazo, P., Sánchez-Penim, A., Sánchez-Blanco, E., Tulloch, S., Velázquez, M., Vílchez Medina, José Manuel, Zamorano, J., Aguerri, A. L., Barrado y Navascués, David, Berlanas, S. R., Bertone, E., Cava, A., Catalán-Torrecilla, C., Cenarro, J., Chávez, M., Dullo, B. T., García, M., García-Rojas, J., Guichard, J., González Delgado, Rosa M., Guzmán, R., Herrero, A., Huélamo, Nuria, Hughes, D. H., Jiménez-Vicente, J., Kehrig, C., Marino, R.A., Márquez, Isabel, Masegosa, Josefa, Mayya, D., Méndez-Abreu, J., Mollá, M., Muñoz-Tuñón, C., Peimbert, M., Pérez-González, Pablo G., Pérez Montero, Enrique, Rodríguez, M., Rodríguez-Espinosa, J. M., Rodríguez Merino, L., Rodríguez-Muñoz, L., Rosa González, Daniel, Sánchez-Almeida, J., Sánchez Contreras, C., Sánchez-Blázquez, P., Sánchez, Sebastián F., Sarajedini, A., Silich, S., Simón-Díaz, S., Tenorio-Tagle, G., Terlevich, E., Terlevich, R., Torres-Peimbert, S., Trujillo, I., Tsamis, Y., Vega, O., Gil de Paz, A., Carrasco, E., Gallego, J., Iglesias-Páramo, J., Cedazo, R., García-Vargas, M. L., Arrillaga, X., Avilés, J. L., Bouquin, A., Carbajo, J., Cardiel, Nicolás, Carrera, M. A., Castillo-Morales, A., Castillo-Domínguez, E., Esteban San Román, S., Ferrusca, D., Gómez-Álvarez, P., Izazaga-Pérez, R., Lefort, B., López-Orozco, J. A., Maldonado, M., Martínez-Delgado, I., Morales-Durán, I., Mújica, E., Páez, G., Pascual, S., Pérez-Calpena, A., Picazo, P., Sánchez-Penim, A., Sánchez-Blanco, E., Tulloch, S., Velázquez, M., Vílchez Medina, José Manuel, Zamorano, J., Aguerri, A. L., Barrado y Navascués, David, Berlanas, S. R., Bertone, E., Cava, A., Catalán-Torrecilla, C., Cenarro, J., Chávez, M., Dullo, B. T., García, M., García-Rojas, J., Guichard, J., González Delgado, Rosa M., Guzmán, R., Herrero, A., Huélamo, Nuria, Hughes, D. H., Jiménez-Vicente, J., Kehrig, C., Marino, R.A., Márquez, Isabel, Masegosa, Josefa, Mayya, D., Méndez-Abreu, J., Mollá, M., Muñoz-Tuñón, C., Peimbert, M., Pérez-González, Pablo G., Pérez Montero, Enrique, Rodríguez, M., Rodríguez-Espinosa, J. M., Rodríguez Merino, L., Rodríguez-Muñoz, L., Rosa González, Daniel, Sánchez-Almeida, J., Sánchez Contreras, C., Sánchez-Blázquez, P., Sánchez, Sebastián F., Sarajedini, A., Silich, S., Simón-Díaz, S., Tenorio-Tagle, G., Terlevich, E., Terlevich, R., Torres-Peimbert, S., Trujillo, I., Tsamis, Y., and Vega, O.

Abstract

On June 25th 2017, the new intermediate-resolution optical IFU and MOS of the 10.4-m GTC had its first light. As part of the tests carried out to verify the performance of the instrument in its two modes (IFU and MOS) and 18 spectral setups (identical number of VPHs with resolutions R=6000-20000 from 0.36 to 1 micron) a number of astronomical objects were observed. These observations show that MEGARA@GTC is called to fill a niche of high-throughput, intermediateresolution IFU and MOS observations of extremely-faint narrow-lined objects. Lyman-¿ absorbers, star-forming dwarfs or even weak absorptions in stellar spectra in our Galaxy or in the Local Group can now be explored to a new level. Thus, the versatility of MEGARA in terms of observing modes and spectral resolution and coverage will allow GTC to go beyond current observational limits in either depth or precision for all these objects. The results to be presented in this talk clearly demonstrate the potential of MEGARA in this regard. © 2018 SPIE.

Published
2018

12. WEAVE an overview and status update

Author

Bonifacio, P., Dalton, G., Trager, S., Aguerri, A. L., Carrasco, E., Vallenari, A., Abrams, D. C., Middleton, K., Sayède, F., Reylé, C., and Astronomy

Subjects
Instrumentation: spectrographs, Surveys
Abstract

The WHT Enhanced Area Velocity Explorer is a high multiplex, multi-object spectrograph that will equip the prime focus of the WHT 4.2m telescope. The instrument is currently in the construction phase and several components have already been procured. I will give a short overview of the instrument and of the project and its status. The French participation is done through CNRS - Institut National des Sciences de l'Univers and the technical activity is carried out, at this stage, at GEPI, Observatoire de Paris.

Published
2016

13. MEGARA, the new intermediate-resolution optical IFU and MOS for GTC: getting ready for the telescope

Author

Evans, Christopher J., Simard, Luc, Takami, Hideki, Gil de Paz, A., Carrasco, E., Gallego, J., Iglesias-Páramo, J., Cedazo, R., García Vargas, M. L., Arrillaga, X., Avilés, J. L., Cardiel, N., Carrera, M. A., Castillo-Morales, A., Castillo-Domínguez, E., de la Cruz García, J. M., Esteban San Román, S., Ferrusca, D., Gómez-Álvarez, P., Izazaga-Pérez, R., Lefort, B., López-Orozco, J. A., Maldonado, M., Martínez-Delgado, I., Morales Durán, I., Mujica, E., Páez, G., Pascual, S., Pérez-Calpena, A., Picazo, P., Sánchez-Penim, A., Sánchez-Blanco, E., Tulloch, S., Velázquez, M., Vílchez, J. M., Zamorano, J., Aguerri, A. L., Barrado y Naváscues, D., Bertone, E., Cava, A., Cenarro, J., Chávez, M., García, M., García-Rojas, J., Guichard, J., González-Delgado, R., Guzmán, R., Herrero, A., Huélamo, N., Hughes, D. H., Jiménez-Vicente, J., Kehrig, C., Marino, R. A., Márquez, I., Masegosa, J., Mayya, Y. D., Méndez-Abreu, J., Mollá, M., Muñoz-Tuñón, C., Peimbert, M., Pérez-González, P. G., Pérez Montero, E., Rodríguez, M., Rodríguez-Espinosa, J. M., Rodríguez-Merino, L., Rodríguez-Muñoz, L., Rosa-González, D., Sánchez-Almeida, J., Sánchez Contreras, C., Sánchez-Blázquez, P., Sánchez Moreno, F. M., Sánchez, S. F., Sarajedini, A., Silich, S., Simón-Díaz, S., Tenorio-Tagle, G., Terlevich, E., Terlevich, R., Torres-Peimbert, S., Trujillo, I., Tsamis, Y., Vega, O., and UAM. Departamento de Física Teórica

Subjects
Astrofísica, Optical fiber, Techniques: spectroscopic, Instrumentation: spectrographs, 01 natural sciences, spectroscopic [Techniques], Spiral, law.invention, 010309 optics, Telescope, Optics, Cosmic web, law, 0103 physical sciences, Local Group [Galaxies], spectrographs [Instrumentation], Galaxies: Local Group, Spectral resolution, 010303 astronomy & astrophysics, Spectrograph, ISM: kinematics and dynamics, Physics, business.industry, Resolution (electron density), Kinematics and dynamics, Física, Astronomía, kinematics and dynamics [ISM], business
Abstract

A. Gil de Paz... et al. "MEGARA, the new intermediate-resolution optical IFU and MOS for GTC: getting ready for the telescope". Ground-based and Airborne Instrumentation for Astronomy VI, Proc.SPIE 9908 ( (4 August 2016); doi: 10.1117/12.2231988. Copyright 2016 Society of Photo‑Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited., Proceedings of the VI Ground-based and Airborne Instrumentation for Astronomy Conference (Edinburgh, United Kingdom), MEGARA (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) is an optical Integral-Field Unit (IFU) and Multi-Object Spectrograph (MOS) designed for the GTC 10.4m telescope in La Palma that is being built by a Consortium led by UCM (Spain) that also includes INAOE (Mexico), IAA-CSIC (Spain), and UPM (Spain). The instrument is currently finishing AIV and will be sent to GTC on November 2016 for its on-sky commissioning on April 2017. The MEGARA IFU fiber bundle (LCB) covers 12.5x11.3 arcsec2 with a spaxel size of 0.62 arcsec while the MEGARA MOS mode allows observing up to 92 objects in a region of 3.5x3.5 arcmin 2 around the IFU. The IFU and MOS modes of MEGARA will provide identical intermediate-to-high spectral resolutions (RFWHM∼6,000, 12,000 and 18,700, respectively for the low-, mid- and high-resolution Volume Phase Holographic gratings) in the range 3700-9800 ÄA. An x-y mechanism placed at the pseudo-slit position allows (1) exchanging between the two observing modes and (2) focusing the spectrograph for each VPH setup. The spectrograph is a collimator-camera system that has a total of 11 VPHs simultaneously available (out of the 18 VPHs designed and being built) that are placed in the pupil by means of a wheel and an insertion mechanism. The custom-made cryostat hosts a 4kx4k 15-μm CCD. The unique characteristics of MEGARA in terms of throughput and versatility and the unsurpassed collecting are of GTC make of this instrument the most efficient tool to date to analyze astrophysical objects at intermediate spectral resolutions. In these proceedings we present a summary of the instrument characteristics and the results from the AIV phase. All subsystems have been successfully integrated and the system-level AIV phase is progressing as expected

Published
2016

14. The Mice at play in the CALIFA survey

Author

Wild, Vivienne, Rosales-Ortega, Fabian, Falcón-Barroso, Jesus, García-Benito, Rubén, Gallazzi, Anna, Delgado, Rosa M. González, Bekeraité, Simona, Pasquali, Anna, Johansson, Peter H., Lorenzo, Begoña García, van de Ven, Glenn, Pawlik, Milena, Peréz, Enrique, Monreal-Ibero, Ana, Lyubenova, Mariya, Fernandes, Roberto Cid, Méndez-Abreu, Jairo, Barrera-Ballesteros, Jorge, Kehrig, Carolina, Iglesias-Páramo, Jorge, Bomans, Dominik J., Márquez, Isabel, Johnson, Benjamin D., Kennicutt, Robert C., Husemann, Bernd, Mast, Damian, Sánchez, Sebastian F., Jakob Walcher, C., Alves, João, Aguerri, Alfonso L., Herrero, Almudena Alonso, Bland-Hawthorn, Joss, Catalán-Torrecilla, Cristina, Florido, Estrella, Gomes, Jean Michel, Jahnke, Knud, López-Sánchez, Á. R., de Lorenzo-Cáceres, Adriana, Marino, Raffaella A., Mármol-Queraltó, Esther, Olden, Patrick, del Olmo, Ascensión, Papaderos, Polychronis, Quirrenbach, Andreas, Vílchez, Jose M., Ziegler, Bodo, Dark Cosmology Centre (DARK), Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), Turbulence Research Laboratory [Goteborg], Chalmers University of Technology [Göteborg], Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Universidad de Jaén (UJA), North Atlantic Treaty Organization (NATO) Science and Technology Organization (STO) Centre for Maritime Research and Experimentation (CMRE), Anglo-Australian Observatory (AAO), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Landessternwarte Königstuhl [ZAH] (LSW), Universität Heidelberg [Heidelberg] = Heidelberg University, Analytical Chemistry, Universidad de Granada = University of Granada (UGR), Universität Wien, University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Universität Heidelberg [Heidelberg], and University of Granada [Granada]

Subjects
[PHYS]Physics [physics], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2014
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15. MEGARA, the new intermediate-resolution optical IFU and MOS for GTC: getting ready for the telescope

Author

Gil de Paz, A., additional, Carrasco, E., additional, Gallego, J., additional, Iglesias-Páramo, J., additional, Cedazo, R., additional, García Vargas, M. L., additional, Arrillaga, X., additional, Avilés, J. L., additional, Cardiel, N., additional, Carrera, M. A., additional, Castillo-Morales, A., additional, Castillo-Domínguez, E., additional, de la Cruz García, J. M., additional, Esteban San Román, S., additional, Ferrusca, D., additional, Gómez-Álvarez, P., additional, Izazaga-Pérez, R., additional, Lefort, B., additional, López-Orozco, J. A., additional, Maldonado, M., additional, Martínez-Delgado, I., additional, Morales Durán, I., additional, Mujica, E., additional, Páez, G., additional, Pascual, S., additional, Pérez-Calpena, A., additional, Picazo, P., additional, Sánchez-Penim, A., additional, Sánchez-Blanco, E., additional, Tulloch, S., additional, Velázquez, M., additional, Vílchez, J. M., additional, Zamorano, J., additional, Aguerri, A. L., additional, Barrado y Naváscues, D., additional, Bertone, E., additional, Cava, A., additional, Cenarro, J., additional, Chávez, M., additional, García, M., additional, García-Rojas, J., additional, Guichard, J., additional, González-Delgado, R., additional, Guzmán, R., additional, Herrero, A., additional, Huélamo, N., additional, Hughes, D. H., additional, Jiménez-Vicente, J., additional, Kehrig, C., additional, Marino, R. A., additional, Márquez, I., additional, Masegosa, J., additional, Mayya, Y. D., additional, Méndez-Abreu, J., additional, Mollá, M., additional, Muñoz-Tuñón, C., additional, Peimbert, M., additional, Pérez-González, P. G., additional, Pérez Montero, E., additional, Rodríguez, M., additional, Rodríguez-Espinosa, J. M., additional, Rodríguez-Merino, L., additional, Rodríguez-Muñoz, L., additional, Rosa-González, D., additional, Sánchez-Almeida, J., additional, Sánchez Contreras, C., additional, Sánchez-Blázquez, P., additional, Sánchez Moreno, F. M., additional, Sánchez, S. F., additional, Sarajedini, A., additional, Silich, S., additional, Simón-Díaz, S., additional, Tenorio-Tagle, G., additional, Terlevich, E., additional, Terlevich, R., additional, Torres-Peimbert, S., additional, Trujillo, I., additional, Tsamis, Y., additional, and Vega, O., additional

Published
2016
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16. MEGARA: a new generation optical spectrograph for GTC

Author

Gil de Paz, A., additional, Gallego, J., additional, Carrasco, E., additional, Iglesias-Páramo, J., additional, Cedazo, R., additional, Vílchez, J. M., additional, García-Vargas, M. L., additional, Arrillaga, X., additional, Carrera, M. A., additional, Castillo-Morales, A., additional, Castillo-Domínguez, E., additional, Eliche-Moral, M. C., additional, Ferrusca, D., additional, González-Guardia, E., additional, Lefort, B., additional, Maldonado, M., additional, Marino, R. A., additional, Martínez-Delgado, I., additional, Morales Durán, I., additional, Mujica, E., additional, Páez, G., additional, Pascual, S., additional, Pérez-Calpena, A., additional, Sánchez-Penim, A., additional, Sánchez-Blanco, E., additional, Tulloch, S., additional, Velázquez, M., additional, Zamorano, J., additional, Aguerri, A. L., additional, Barrado y Naváscues, D., additional, Bertone, E., additional, Cardiel, N., additional, Cava, A., additional, Cenarro, J., additional, Chávez, M., additional, García, M., additional, Guichard, J., additional, Gúzman, R., additional, Herrero, A., additional, Huélamo, N., additional, Hughes, D., additional, Jiménez-Vicente, J., additional, Kehrig, C., additional, Márquez, I., additional, Masegosa, J., additional, Mayya, Y. D., additional, Méndez-Abreu, J., additional, Mollá, M., additional, Muñoz-Tuñón, C., additional, Peimbert, M., additional, Pérez-González, P. G., additional, Pérez Montero, E., additional, Rodríguez, M., additional, Rodríguez-Espinosa, J. M., additional, Rodríguez-Merino, L., additional, Rosa-González, D., additional, Sánchez-Almeida, J., additional, Sánchez Contreras, C., additional, Sánchez-Blázquez, P., additional, Sánchez Moreno, F. M., additional, Sánchez, S. F., additional, Sarajedini, A., additional, Serena, F., additional, Silich, S., additional, Simón-Díaz, S., additional, Tenorio-Tagle, G., additional, Terlevich, E., additional, Terlevich, R., additional, Torres-Peimbert, S., additional, Trujillo, I., additional, Tsamis, Y., additional, Vega, O., additional, and Villar, V., additional

Published
2014
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17. MEGARA: the future optical IFU and multi-object spectrograph for the 10.4m GTC telescope

Author

Gil de Paz, A., primary, Carrasco, E., additional, Gallego, J., additional, Sánchez, F. M., additional, Vílchez Medina, J. M., additional, García-Vargas, M. L., additional, Arrillaga, X., additional, Carrera, M. A., additional, Castillo-Morales, A., additional, Castillo-Domínguez, E., additional, Cedazo, R., additional, Eliche-Moral, C., additional, Ferrusca, D., additional, González-Guardia, E., additional, Maldonado, M., additional, Marino, R. A., additional, Martínez-Delgado, I., additional, Morales Durán, I., additional, Mújica, E., additional, Pascual, S., additional, Pérez-Calpena, A., additional, Sánchez-Penim, A., additional, Sánchez-Blanco, E., additional, Serena, F., additional, Tulloch, S., additional, Villar, V., additional, Zamorano, J., additional, Barrado y Naváscues, D., additional, Bertone, E., additional, Cardiel, N., additional, Cava, A., additional, Cenarro, J., additional, Chávez, M., additional, García, M., additional, Guichard, J., additional, Gúzman, R., additional, Herrero, A., additional, Huélamo, N., additional, Hughes, D., additional, Iglesias, J., additional, Jiménez-Vicente, J., additional, Aguerri, A. L., additional, Mayya, D., additional, Abreu, J. M., additional, Mollá, M., additional, Muñoz-Tuñón, C., additional, Peimbert, S., additional, Peimbert, M., additional, Pérez-González, P. G., additional, Pérez Montero, E., additional, Rodríguez, M., additional, Rodríguez-Espinosa, J. M., additional, Rodríguez-Merino, L., additional, Rosa, D., additional, Sánchez-Almeida, J., additional, Sánchez Contreras, C., additional, Sánchez-Blázquez, Patricia, additional, Sánchez, S., additional, Sarajedini, A., additional, Silich, S., additional, Simón, S., additional, Tenorio-Tagle, G., additional, Terlevich, E., additional, Terlevich, R., additional, Trujillo, I., additional, Tsamis, Y., additional, and Vega, O., additional

Published
2012
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18. THE HST /ACS COMA CLUSTER SURVEY. II. DATA DESCRIPTION AND SOURCE CATALOGS

Author

Hammer, Derek, primary, Verdoes Kleijn, Gijs, additional, Hoyos, Carlos, additional, den Brok, Mark, additional, Balcells, Marc, additional, Ferguson, Henry C., additional, Goudfrooij, Paul, additional, Carter, David, additional, Guzmán, Rafael, additional, Peletier, Reynier F., additional, Smith, Russell J., additional, Graham, Alister W., additional, Trentham, Neil, additional, Peng, Eric, additional, Puzia, Thomas H., additional, Lucey, John R., additional, Jogee, Shardha, additional, Aguerri, Alfonso L., additional, Batcheldor, Dan, additional, Bridges, Terry J., additional, Chiboucas, Kristin, additional, Davies, Jonathan I., additional, del Burgo, Carlos, additional, Erwin, Peter, additional, Hornschemeier, Ann, additional, Hudson, Michael J., additional, Huxor, Avon, additional, Jenkins, Leigh, additional, Karick, Arna, additional, Khosroshahi, Habib, additional, Kourkchi, Ehsan, additional, Komiyama, Yutaka, additional, Lotz, Jennifer, additional, Marzke, Ronald O., additional, Marinova, Irina, additional, Matkovic, Ana, additional, Merritt, David, additional, Miller, Bryan W., additional, Miller, Neal A., additional, Mobasher, Bahram, additional, Mouhcine, Mustapha, additional, Okamura, Sadanori, additional, Percival, Sue, additional, Phillipps, Steven, additional, Poggianti, Bianca M., additional, Price, James, additional, Sharples, Ray M., additional, Tully, R. Brent, additional, and Valentijn, Edwin, additional

Published
2010
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19. TheHubble Space TelescopeAdvanced Camera for Surveys Coma Cluster Survey. I. Survey Objectives and Design

Author

Carter, David, primary, Goudfrooij, Paul, additional, Mobasher, Bahram, additional, Ferguson, Henry C., additional, Puzia, Thomas H., additional, Aguerri, Alfonso L., additional, Balcells, Marc, additional, Batcheldor, Dan, additional, Bridges, Terry J., additional, Davies, Jonathan I., additional, Erwin, Peter, additional, Graham, Alister W., additional, Guzmán, Rafael, additional, Hammer, Derek, additional, Hornschemeier, Ann, additional, Hoyos, Carlos, additional, Hudson, Michael J., additional, Huxor, Avon, additional, Jogee, Shardha, additional, Komiyama, Yutaka, additional, Lotz, Jennifer, additional, Lucey, John R., additional, Marzke, Ronald O., additional, Merritt, David, additional, Miller, Bryan W., additional, Miller, Neal A., additional, Mouhcine, Mustapha, additional, Okamura, Sadanori, additional, Peletier, Reynier F., additional, Phillipps, Steven, additional, Poggianti, Bianca M., additional, Sharples, Ray M., additional, Smith, Russell J., additional, Trentham, Neil, additional, Tully, R. Brent, additional, Valentijn, Edwin, additional, and Verdoes Kleijn, Gijs, additional

Published
2008
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20. The Hubble Space Telescope Advanced Camera for Surveys Coma Cluster Survey. I. Survey Objectives and DesignBased on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. These observations are associated with program GO10861.

Author

Carter, David, Goudfrooij, Paul, Mobasher, Bahram, Ferguson, Henry C., Puzia, Thomas H., Aguerri, Alfonso L., Balcells, Marc, Batcheldor, Dan, Bridges, Terry J., Davies, Jonathan I., Erwin, Peter, Graham, Alister W., Guzmán, Rafael, Hammer, Derek, Hornschemeier, Ann, Hoyos, Carlos, Hudson, Michael J., Huxor, Avon, Jogee, Shardha, and Komiyama, Yutaka

Published
2008
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21. MEGARA: a new generation optical spectrograph for GTC

Author

Ramsay, Suzanne K., McLean, Ian S., Takami, Hideki, Gil de Paz, A., Gallego, J., Carrasco, E., Iglesias-Páramo, J., Cedazo, R., Vílchez, J. M., García-Vargas, M. L., Arrillaga, X., Carrera, M. A., Castillo-Morales, A., Castillo-Domínguez, E., Eliche-Moral, M. C., Ferrusca, D., González-Guardia, E., Lefort, B., Maldonado, M., Marino, R. A., Martínez-Delgado, I., Morales Durán, I., Mujica, E., Páez, G., Pascual, S., Pérez-Calpena, A., Sánchez-Penim, A., Sánchez-Blanco, E., Tulloch, S., Velázquez, M., Zamorano, J., Aguerri, A. L., Barrado y Naváscues, D., Bertone, E., Cardiel, N., Cava, A., Cenarro, J., Chávez, M., García, M., Guichard, J., Gúzman, R., Herrero, A., Huélamo, N., Hughes, D., Jiménez-Vicente, J., Kehrig, C., Márquez, I., Masegosa, J., Mayya, Y. D., Méndez-Abreu, J., Mollá, M., Muñoz-Tuñón, C., Peimbert, M., Pérez-González, P. G., Pérez Montero, E., Rodríguez, M., Rodríguez-Espinosa, J. M., Rodríguez-Merino, L., Rosa-González, D., Sánchez-Almeida, J., Sánchez Contreras, C., Sánchez-Blázquez, P., Sánchez Moreno, F. M., Sánchez, S. F., Sarajedini, A., Serena, F., Silich, S., Simón-Díaz, S., Tenorio-Tagle, G., Terlevich, E., Terlevich, R., Torres-Peimbert, S., Trujillo, I., Tsamis, Y., Vega, O., and Villar, V.

Published
2014
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22. The Resolved Stellar Populations of a Dwarf Spheroidal Galaxy in the Virgo Cluster

Author

Durrell, Patrick R., Williams, Benjamin F., Ciardullo, Robin, Feldmeier, John J., von, Ted, Sigurdsson, Steinn, Jacoby, George H., Ferguson, Henry C., Tanvir, Nial R., Arnaboldi, Magda, Gerhard, Ortwin, Aguerri, Alfonso L., Freeman, Ken, and Vinciguerra, Matt

Abstract

We report on the discovery of a faint (MV ~ -10.6 +- 0.2) dwarf spheroidal galaxy on deep F606W and F814W Hubble Space Telescope images of a Virgo intracluster field. The galaxy is easily resolved in our images, as our color magnitude diagram (CMD) extends [?]1 magnitude beyond the tip of the red giant branch (RGB). Thus, it is the deepest CMD for a small dwarf galaxy inside a cluster environment. Using the colors of the RGB stars, we derive a metal abundance for the dwarf of [M/H] = -2.3 +- 0.3 and show that the metallicity dispersion is less than 0.6 dex at 95% confidence. We also use the galaxy's lack of AGB stars and the absence of objects brighter than Mbol ~ -4.1 +- 0.2 to show that the system is old (t [?] 10 Gyr). Finally, we derive the object's structural parameters and show that the galaxy displays no obvious evidence of tidal threshing. Since the tip of the red giant branch distance [(m - M)0 = 31.23 +- 0.17 or D = 17.6 +- 1.4 Mpc] puts the galaxy near the core of the Virgo cluster, one might expect the object to have undergone some tidal processing. Yet the chemical and morphological similarity between the dwarf and the dSph galaxies of the Local and M81 Group demonstrates that the object is indeed pristine and not the shredded remains of a much larger galaxy. We discuss the possible origins of this galaxy and suggest that it is just now falling into Virgo for the first time.

Published
2007

23. The Metallicity Distribution of Intracluster Stars in Virgo

Author

Williams, Benjamin F., Ciardullo, Robin, Durrell, Patrick R., Vinciguerra, Matt, Feldmeier, John J., Jacoby, George H., Sigurdsson, Steinn, von, Ted, Ferguson, Henry C., Tanvir, Nial R., Arnaboldi, Magda, Gerhard, Ortwin, Aguerri, Alfonso L., and Freeman, Ken

Abstract

We have used the Hubble Space Telescope's Advanced Camera for Surveys (ACS) to detect and measure ~5300 stars in a single intracluster field in the Virgo Cluster. By performing F606W and F814W photometry on these stars, we have determined their metallicity distribution function and constrained the types of stars present in this portion of Virgo's intracluster space. Based on the small number of stars detected that were brighter than the red giant branch (RGB) tip, we suggest that in this region, Virgo's intracluster stars are mostly old ([?]10 Gyr). Through analysis of the RGB stars themselves, we determine that the population contains the full range of metallicities probed (-2.3 [?] [M/H] [?] 0.0). We also present evidence that the younger ([?]10 Gyr) component of the population is more metal-rich, with [M/H] > -0.5. The spatial distribution of the most metal-poor stars in the field shows significantly more structure than that of the metal-rich stars, indicating that the intracluster population is not well mixed. We discuss the implications that these observations have for the production of intracluster stars and the dynamical evolution of the Virgo Cluster.

Published
2007

24. Virgo's Intracluster Globular Clusters as Seen by the Advanced Camera for Surveys

Author

Williams, Benjamin F., Ciardullo, Robin, Durrell, Patrick R., Feldmeier, John J., Sigurdsson, Steinn, Vinciguerra, Matt, Jacoby, George H., von, Ted, Ferguson, Henry C., Tanvir, Nial R., Arnaboldi, Magda, Gerhard, Ortwin, Aguerri, Alfonso L., and Freeman, Ken C.

Abstract

We report the discovery of four candidate intracluster globular clusters (IGCs) in a single deep HST ACS field of the Virgo Cluster. We show that each cluster is roughly spherical, has a magnitude near the peak of the Virgo globular cluster luminosity function, has a radial profile that is best fitted by a King model, and is surrounded by an excess of point sources that have the colors and magnitudes of cluster red giant stars. Despite the fact that two of our IGC candidates have integrated colors redder than the mean of the M87 globular cluster system, we propose that all of the objects are metal-poor, with [M/H] < -1. We show that the tidal radii of our intracluster globular clusters are all larger than the mean for Milky Way clusters and suggest that the clusters have undergone less tidal stress than their Galactic counterparts. Finally, we normalize our globular cluster observations to the luminosity of intracluster stars and derive a value of SN ~ 6 for the specific frequency of Virgo intracluster globular clusters. We use these data to constrain the origins of Virgo's intracluster population and suggest that globular clusters in our intracluster field have a different origin than globular clusters in the vicinity of M87. In particular, we argue that dwarf elliptical galaxies may be an important source of intracluster stars.

Published
2007

25. Intracluster Stellar Population Properties from N-Body Cosmological Simulations. I. Constraints at z = 0

Author

Napolitano, Nicola R., Pannella, Maurilio, Arnaboldi, Magda, Gerhard, Ortwin, Aguerri, Alfonso L., Freeman, Kenneth C., Capaccioli, Massimo, Ghigna, Sebastiano, Governato, Fabio, Quinn, Tom, and Stadel, Joachim

Abstract

We use a high-resolution collisionless simulation of a Virgo-like cluster in a LCDM cosmology to determine the velocity and clustering properties of the diffuse stellar component in the intracluster region at the present epoch. The simulated cluster builds up hierarchically and tidal interactions between member galaxies and the cluster potential produce a diffuse stellar component free-flying in the intracluster medium. Here we adopt an empirical scheme to identify tracers of the stellar component in the simulation and hence study its properties. We find that at z = 0 the intracluster stellar light is mostly unrelaxed in velocity space and clustered in structures whose typical clustering radii are about 50 kpc at R = 400-500 kpc from the cluster center, and we predict the radial velocity distribution expected in spectroscopic follow-up surveys. Finally, we compare the spatial clustering in the simulation with the properties of the Virgo intracluster stellar population, as traced by ongoing intracluster planetary nebula surveys in Virgo. The preliminary results indicate a substantial agreement with the observed clustering properties of the diffuse stellar population in Virgo.

Published
2003

26. WEAVE an overview and status update

Author

Bonifacio, P., Gavin Dalton, Trager, S., Aguerri, A. L., Carrasco, E., Vallenari, A., Abrams, D. C., Middleton, K., Sayède, F., and ITA

Abstract

The WHT Enhanced Area Velocity Explorer is a high multiplex, multi-object spectrograph that will equip the prime focus of the WHT 4.2m telescope. The instrument is currently in the construction phase and several components have already been procured. I will give a short overview of the instrument and of the project and its status. The French participation is done through CNRS - Institut National des Sciences de l'Univers and the technical activity is carried out, at this stage, at GEPI, Observatoire de Paris.

27. The ALHAMBRA Survey: Bayesian Photometric Redshifts with 23 bands for 3 squared degrees

Author

Molino, A., Benítez, N., Moles, M., Fernández-Soto, A., Cristóbal-Hornillos, D., Ascaso, B., Jiménez-Teja, Y., Schoenell, W., Pablo Arnalte-Mur, Pović, M., Coe, D., López-Sanjuan, C., Díaz-García, L. A., Varela, J., Matute, I., Masegosa, J., Márquez, I., Perea, J., Del Olmo, A., Husillos, C., Alfaro, E., Aparicio-Villegas, T., Cerviño, M., Huertas-Company, M., Aguerri, A. L., Broadhurst, T., Cabrera-Caño, J., Cepa, J., González Delgado, R. M., Infante, L., Martínez, V. J., Prada, F., and Quintana, J. M.

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), FOS: Physical sciences, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The ALHAMBRA (Advance Large Homogeneous Area Medium Band Redshift Astronomical) survey has observed 8 different regions of the sky, including sections of the COSMOS, DEEP2, ELAIS, GOODS-N, SDSS and Groth fields using a new photometric system with 20 contiguous ~ $300\AA$ filters covering the optical range, combining them with deep $JHKs$ imaging. The observations, carried out with the Calar Alto 3.5m telescope using the wide field (0.25 sq. deg FOV) optical camera LAICA and the NIR instrument Omega-2000, correspond to ~700hrs on-target science images. The photometric system was designed to maximize the effective depth of the survey in terms of accurate spectral-type and photo-zs estimation along with the capability of identification of relatively faint emission lines. Here we present multicolor photometry and photo-zs for ~438k galaxies, detected in synthetic F814W images, complete down to I~24.5 AB, taking into account realistic noise estimates, and correcting by PSF and aperture effects with the ColorPro software. The photometric ZP have been calibrated using stellar transformation equations and refined internally, using a new technique based on the highly robust photometric redshifts measured for emission line galaxies. We calculate photometric redshifts with the BPZ2 code, which includes new empirically calibrated templates and priors. Our photo-zs have a precision of $dz/(1+z_s)=1%$ for I=0.56 for I=0.86 for I, Comment: The catalog data and a full resolution version of this paper is available at https://cloud.iaa.csic.es/alhambra/

28. MEGARA, the new intermediate-resolution optical IFU and MOS for GTC: getting ready for the telescope

Author

Evans, Christopher J., Simard, Luc, Takami, Hideki, Gil de Paz, A., Carrasco, E., Gallego, J., Iglesias-Páramo, J., Cedazo, R., García Vargas, M. L., Arrillaga, X., Avilés, J. L., Cardiel, N., Carrera, M. A., Castillo-Morales, A., Castillo-Domínguez, E., de la Cruz García, J. M., Esteban San Román, S., Ferrusca, D., Gómez-Álvarez, P., Izazaga-Pérez, R., Lefort, B., López-Orozco, J. A., Maldonado, M., Martínez-Delgado, I., Morales Durán, I., Mujica, E., Páez, G., Pascual, S., Pérez-Calpena, A., Picazo, P., Sánchez-Penim, A., Sánchez-Blanco, E., Tulloch, S., Velázquez, M., Vílchez, J. M., Zamorano, J., Aguerri, A. L., Barrado y Naváscues, D., Bertone, E., Cava, A., Cenarro, J., Chávez, M., García, M., García-Rojas, J., Guichard, J., González-Delgado, R., Guzmán, R., Herrero, A., Huélamo, N., Hughes, D. H., Jiménez-Vicente, J., Kehrig, C., Marino, R. A., Márquez, I., Masegosa, J., Mayya, Y. D., Méndez-Abreu, J., Mollá, M., Muñoz-Tuñón, C., Peimbert, M., Pérez-González, P. G., Pérez Montero, E., Rodríguez, M., Rodríguez-Espinosa, J. M., Rodríguez-Merino, L., Rodríguez-Muñoz, L., Rosa-González, D., Sánchez-Almeida, J., Sánchez Contreras, C., Sánchez-Blázquez, P., Sánchez Moreno, F. M., Sánchez, S. F., Sarajedini, A., Silich, S., Simón-Díaz, S., Tenorio-Tagle, G., Terlevich, E., Terlevich, R., Torres-Peimbert, S., Trujillo, I., Tsamis, Y., Vega, O., Evans, Christopher J., Simard, Luc, Takami, Hideki, Gil de Paz, A., Carrasco, E., Gallego, J., Iglesias-Páramo, J., Cedazo, R., García Vargas, M. L., Arrillaga, X., Avilés, J. L., Cardiel, N., Carrera, M. A., Castillo-Morales, A., Castillo-Domínguez, E., de la Cruz García, J. M., Esteban San Román, S., Ferrusca, D., Gómez-Álvarez, P., Izazaga-Pérez, R., Lefort, B., López-Orozco, J. A., Maldonado, M., Martínez-Delgado, I., Morales Durán, I., Mujica, E., Páez, G., Pascual, S., Pérez-Calpena, A., Picazo, P., Sánchez-Penim, A., Sánchez-Blanco, E., Tulloch, S., Velázquez, M., Vílchez, J. M., Zamorano, J., Aguerri, A. L., Barrado y Naváscues, D., Bertone, E., Cava, A., Cenarro, J., Chávez, M., García, M., García-Rojas, J., Guichard, J., González-Delgado, R., Guzmán, R., Herrero, A., Huélamo, N., Hughes, D. H., Jiménez-Vicente, J., Kehrig, C., Marino, R. A., Márquez, I., Masegosa, J., Mayya, Y. D., Méndez-Abreu, J., Mollá, M., Muñoz-Tuñón, C., Peimbert, M., Pérez-González, P. G., Pérez Montero, E., Rodríguez, M., Rodríguez-Espinosa, J. M., Rodríguez-Merino, L., Rodríguez-Muñoz, L., Rosa-González, D., Sánchez-Almeida, J., Sánchez Contreras, C., Sánchez-Blázquez, P., Sánchez Moreno, F. M., Sánchez, S. F., Sarajedini, A., Silich, S., Simón-Díaz, S., Tenorio-Tagle, G., Terlevich, E., Terlevich, R., Torres-Peimbert, S., Trujillo, I., Tsamis, Y., and Vega, O.

Abstract

MEGARA (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) is an optical Integral-Field Unit (IFU) and Multi-Object Spectrograph (MOS) designed for the GTC 10.4m telescope in La Palma that is being built by a Consortium led by UCM (Spain) that also includes INAOE (Mexico), IAA-CSIC (Spain), and UPM (Spain). The instrument is currently finishing AIV and will be sent to GTC on November 2016 for its on-sky commissioning on April 2017. The MEGARA IFU fiber bundle (LCB) covers 12.5x11.3 arcsec2 with a spaxel size of 0.62 arcsec while the MEGARA MOS mode allows observing up to 92 objects in a region of 3.5x3.5 arcmin2 around the IFU. The IFU and MOS modes of MEGARA will provide identical intermediate-to-high spectral resolutions (RFWHM~6,000, 12,000 and 18,700, respectively for the low-, mid- and high-resolution Volume Phase Holographic gratings) in the range 3700-9800ÅÅ. An x-y mechanism placed at the pseudo-slit position allows (1) exchanging between the two observing modes and (2) focusing the spectrograph for each VPH setup. The spectrograph is a collimator-camera system that has a total of 11 VPHs simultaneously available (out of the 18 VPHs designed and being built) that are placed in the pupil by means of a wheel and an insertion mechanism. The custom-made cryostat hosts a 4kx4k 15-μm CCD. The unique characteristics of MEGARA in terms of throughput and versatility and the unsurpassed collecting are of GTC make of this instrument the most efficient tool to date to analyze astrophysical objects at intermediate spectral resolutions. In these proceedings we present a summary of the instrument characteristics and the results from the AIV phase. All subsystems have been successfully integrated and the system-level AIV phase is progressing as expected.

29. First scientific observations with MEGARA at GTC

Author

Evans, Christopher J., Simard, Luc, Takami, Hideki, Gil de Paz, A., Carrasco, E., Gallego, J., Iglesias-Páramo, J., Cedazo, R., García-Vargas, M. L., Arrillaga, X., Avilés, J. L., Bouquin, A., Carbajo, J., Cardiel, N., Carrera, M. A., Castillo-Morales, A., Castillo-Domínguez, E., Esteban San Román, S., Ferrusca, D., Gómez-Álvarez, P., Izazaga-Pérez, R., Lefort, B., López-Orozco, J. A., Maldonado, M., Martínez-Delgado, I., Morales-Durán, I., Mujica, E., Páez, G., Pascual, S., Pérez-Calpena, A., Picazo, P., Sánchez-Penim, A., Sánchez-Blanco, E., Tulloch, S., Velázquez, M., Vílchez, J. M., Zamorano, J., Aguerri, A. L., Barrado y Navascues, D., Berlanas, S. R., Bertone, E., Cava, A., Catalán-Torrecilla, C., Cenarro, J., Chávez, M., Dullo, B. T., García, M., García-Rojas, J., Guichard, J., González-Delgado, R., Guzmán, R., Herrero, A., Huélamo, N., Hughes, D. H., Jiménez-Vicente, J., Kehrig, C., Marino, R. A., Márquez, I., Masegosa, J., Mayya, D., Méndez-Abreu, J., Mollá, M., Muñoz-Tuñón, C., Peimbert, M., Pérez-González, P. G., Pérez-Montero, E., Rodríguez, M., Rodríguez-Espinosa, J. M., Rodríguez Merino, L., Rodríguez-Muñoz, L., Rosa-González, D., Sánchez-Almeida, J., Sánchez-Contreras, C., Sánchez-Blázquez, P., Sánchez, S. F., Sarajedini, A., Silich, S., Simón-Díaz, S., Tenorio-Tagle, G., Terlevich, E., Terlevich, R., Torres-Peimbert, S., Trujillo, I., Tsamis, Y., and Vega, O.

Published
2018
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30. MEGARA, the R=6000-20000 IFU and MOS of GTC

Author

Evans, Christopher J., Simard, Luc, Takami, Hideki, Carrasco, E., Gil de Paz, A., Gallego, J., Iglesias-Páramo, J., Cedazo, R., García Vargas, M. L., Arrillaga, X., Avilés, J. L., Bouquin, A., Carbajo, J., Cardiel, N., Carrera, M. A., Castillo Morales, A., Castillo-Domínguez, E., Esteban San Román, S., Ferrusca, D., Gómez-Álvarez, P., Izazaga-Pérez, R., Lefort, B., López Orozco, J. A., Maldonado, M., Martínez Delgado, I., Morales Durán, I., Mújica, E., Ortiz, R., Páez, G., Pascual, S., Pérez-Calpena, A., Picazo, P., Sánchez-Penim, A., Sánchez-Blanco, E., Tulloch, S., Velázquez, M., Vílchez, J. M., Zamorano, J., Aguerri, A. L., Barrado, D., Bertone, E., Cava, A., Catalán-Torrecilla, C., Cenarro, J., Chávez, M., Dullo, B. T., Eliche, C., García, Mi., García-Rojas, J., Guichard, J., González-Delgado, R., Guzmán, R., Herrero, A., Huélamo, N., Hughes, D. H., Jiménez-Vicente, J., Kehrig, C., Marino, R. A., Márquez, I., Masegosa, J., Mayya, D., Méndez-Abreu, J., Mollá, M., Muñoz-Tuñón, C., Peimbert, M., Pérez-González, P. G., Pérez-Montero, E., Roca-Fàbrega, S., Rodríguez, M., Rodríguez-Espinosa, J. M., Rodríguez-Merino, L., Rodríguez-Muñoz, L., Rosa-González, D., Sánchez-Almeida, J., Sánchez Contreras, C., Sánchez-Blázquez, P., Sánchez, S. F., Sarajedini, A., Silich, S., Simón-Díaz, S., Tenorio-Tagle, G., Terlevich, E., Terlevich, R., Torres-Peimbert, S., Trujillo, I., Tsamis, Y., and Vega, O.

Published
2018
Full Text
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