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Journal articles on the topic 'Galaxies – Spectres'

Author: Grafiati

Published: 4 June 2021

Last updated: 8 February 2022

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1

Reynolds, T. N., T. Westmeier, and L. Staveley-Smith. "H i deficiencies and asymmetries in HIPASS galaxies." Monthly Notices of the Royal Astronomical Society 499, no. 3 (2020): 3233–42. http://dx.doi.org/10.1093/mnras/staa3126.

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ABSTRACT We present an analysis of the sky distribution of neutral hydrogen (H i) deficiency and spectral asymmetry for galaxies detected by the H i Parkes All-Sky Survey (HIPASS) as a function of projected environment density. Previous studies of galaxy H i deficiency using HIPASS were sensitive to galaxies that are extremely H i rich or poor. We use an updated binning statistic for measuring the global sky distribution of H i deficiency that is sensitive to the average deficiencies. Our analysis confirms the result from previous studies that galaxies residing in denser environments, such as

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Delgado, Rosa González, Enrique Pérez, Roberto Cid Fernandes, et al. "CALIFA survey: The spatially resolved star formation history of massive galaxies." Proceedings of the International Astronomical Union 8, S295 (2012): 300–303. http://dx.doi.org/10.1017/s1743921313005097.

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AbstractThe Calar Alto Legacy Integral Field Area (CALIFA) project is an ongoing 3D spectroscopic survey of 600 nearby galaxies of all kinds. This pioneer survey is providing valuable clues on how galaxies form and evolve. Processed through spectral synthesis techniques, CALIFA datacubes allow us to, for the first time, spatially resolve the star formation history of galaxies spread across the color-magnitude diagram. The richness of this approach is already evident from the results obtained for the first ~ 1/6 of the sample. Here we show how the different galactic spatial sub-components (“bul

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González Delgado, R. M., E. Pérez, R. Cid Fernandes, et al. "The growth of mass and metallicity in bulges and disks: CALIFA perspective." Proceedings of the International Astronomical Union 10, H16 (2012): 338. http://dx.doi.org/10.1017/s1743921314006024.

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AbstractCALIFA (Calar Alto Legacy Integral Field Area) is a 3D spectroscopic survey of 600 nearby galaxies that we are obtaining with PPaK@3.5m at Calar Alto (Sánchez et al. 2012; Husemann et al. 2012). This pioneer survey is providing valuable clues on how the mass and metallicity grow in the different galactic spatial sub-components (“bulge” and “disk”). Processed through spectral synthesis techniques, CALIFA datacubes allow us to, for the first time, spatially resolve the star formation history of galaxies (Cid Fernandes et al. 2012). The richness of this approach is already evident from th

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Franco, M., D. Elbaz, L. Zhou, et al. "GOODS-ALMA: The slow downfall of star formation in z = 2–3 massive galaxies." Astronomy & Astrophysics 643 (October 27, 2020): A30. http://dx.doi.org/10.1051/0004-6361/202038312.

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We investigate the properties of a sample of 35 galaxies, detected with the Atacama Large Millimeter/Submillimeter Array (ALMA) at 1.1 mm in the GOODS-ALMA field (area of 69 arcmin2, resolution = 0.60″, rms ≃ 0.18 mJy beam−1). Using the ultraviolet-to-radio deep multiwavelength coverage of the GOODS–South field, we fit the spectral energy distributions of these galaxies to derive their key physical properties. The galaxies detected by ALMA are among the most massive at z = 2−4 (M⋆, med = 8.5 × 1010 M⊙) and they are either starburst or located in the upper part of the galaxy star-forming main s

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Briggs, F. H. "VLBI Studies of High-Redshift 21cm Absorption Lines." Symposium - International Astronomical Union 129 (1988): 211. http://dx.doi.org/10.1017/s0074180900134503.

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VLBI experiments can contribute to our understanding of absorbing gas observed in the spectra of high-redshift quasars by measuring the spatial extent of the absorbers. An optical survey conducted by Wolfe, Turnshek, Smith, and Cohen (1986) has turned up a class of absorbers characterized by large HI column density and a rich spectrum of metal absorption lines. In these respects the absorbers resemble spiral galaxies, but their occurence is too frequent for interception probabilities based on galaxy cross sections at the present epoch. Recent radio observations to determine the nature of such

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Andreasian-Thomas, Nora. "Dusty Active Galaxies." Proceedings of the International Astronomical Union 9, S304 (2013): 65. http://dx.doi.org/10.1017/s1743921314003330.

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AbstractMost astronomers know about B. E. Markarians discovery and further study of galaxies with UV excess. It is less known that in 1963 Markarian drew attention to a small group of galaxies with color index-spectral type discrepancy. Early spectral type of these galaxies is combined with large color index (e.g. M82). Later studies showed that galaxies with large intrinsic color indices (CI ≥ 0.85) exhibit properties typical for active galaxies - galaxies with “red excess” are as active as galaxies with UV excess.

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Sodré, L., and H. Cuevas. "Spectral classification of galaxies." Vistas in Astronomy 38 (January 1994): 287–91. http://dx.doi.org/10.1016/0083-6656(94)90039-6.

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Jackson, C. A., and D. M. Londish. "Spectral Characteristics of the 2dFGRS–NVSS Galaxies." Publications of the Astronomical Society of Australia 17, no. 3 (2000): 234–40. http://dx.doi.org/10.1071/as00042.

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AbstractWe have analysed the 2dF spectra of a sample of galaxies common to the 2dF Galaxy Redshift Survey (2dFGRS, Colless 1999) and the NRAO VLA Sky Survey (NVSS, Condon et al. 1998). Our sample comprises 88 galaxies selected by Sadler et al. (1999) from 30 2dFGRS fields observed in 1998. In this paper we discuss how this and future, much larger, samples of 2dFGRS–NVSS galaxies can be interpreted via analysis of those galaxies with strong narrow emission lines. Using diagnostic line ratio measurements, we confirm the majority of the eyeball classifications of Sadler et al. (1999), although ma

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Denissyuk, E. K., V. N. Gaisina, and R. R. Valiullin. "Spectral Variability of Some Seyfert Galaxies." International Astronomical Union Colloquium 184 (2002): 361–62. http://dx.doi.org/10.1017/s0252921100031031.

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AbstractThe very first spectrograms of 40 Seyfert galaxies are discussed. All these objects were taken from Markarian’s lists of galaxies. They were first investigated and classified at Fesenkov Astrophysical Institute during 1973-1988. Spectral study was carried out with a slit spectrograph, attached to the 70-cm telescope and equipped with a three cascades image-tube. Repeated observations of 22 galaxies were obtained in 1985-2000. An analysis of possible spectral variability of the studied galaxies over 10-26 years was made. A list of objects which are the most interesting for further obser

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Feltre, Anna, Evanthia Hatziminaoglou, Antonio Hernán-Caballero, Jacopo Fritz, and Alberto Franceschini. "AGN and Star Formation in HerMES-IRS sources." Proceedings of the International Astronomical Union 9, S304 (2013): 52–55. http://dx.doi.org/10.1017/s1743921314003305.

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AbstractOne of the remaining open issues in the context of the analysis of Active Galactic Nuclei (AGN) is the evidence that nuclear gravitational accretion is often accompanied by a concurrent starburst activity. We developed a spectral energy distribution (SED) fitting technique to derive simultaneously the physical properties of active galaxies and coexisting starbursts making the best use of Spitzer and Herschel IR observations. We apply the SED fitting procedure to a large sample of extragalactic sources representing the HerMES (Herschel/Multi-tiered Extragalactic Survey) population with

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Gomes, Jean Michel, Mercedes E. Filho, and Luis C. Ho. "Stellar populations in the centers of nearby galaxies." Proceedings of the International Astronomical Union 7, S284 (2011): 234–36. http://dx.doi.org/10.1017/s1743921312009131.

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AbstractThe great amount of data observed in recent years coupled with modelling using evolutionary synthesis codes (BPASS, COELHO, GALAXEV, GALEV, MILES, PÉGASE, etc. . .) to compute Single Stellar Populations (SSPs) and the availability of fast and ingenious spectral synthesis codes such as starlight, ULySS and VESPA, have significantly shed light on our knowledge about the formation and evolution of galaxies. However, there are still open issues concerning the stellar populations in nearby galaxies, particularly those harbouring Active Galactic Nuclei (AGN): can stellar populations mimic nu

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Amram, Philippe. "3D Spectroscopic Surveys of Late-Type Nearby Galaxies in the Optical." Proceedings of the International Astronomical Union 6, S277 (2010): 89–95. http://dx.doi.org/10.1017/s1743921311022538.

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AbstractTwo classes of spectro-imagers are available, the first one, usually based on grisms, allows to cover intermediate fields of view and wide spectral ranges (decreasing when the spectral resolution increases) while the second one, usually based on tunable filters (like Fabry-Perot), is generally able to cover larger fields of view but on narrow spectral ranges (also depending on the spectral resolution). Both families of instrument have access to low or high spectral resolution and are used in seeing limited conditions for observing nearby galaxies. Spectro-imagers provide data cubes con

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Chen, X. Y., Y. C. Liang, F. Hammer, Y. H. Zhao, and G. H. Zhong. "Stellar populations of local infrared-selected galaxies." Proceedings of the International Astronomical Union 5, S262 (2009): 313–14. http://dx.doi.org/10.1017/s1743921310003005.

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AbstractThe stellar populations of 849 local infrared-selected galaxies from SDSS and IRAS (including 419 star-forming galaxies, 326 composite galaxies, 35 Seyfert 2s, and 69 LINERs in 4 spectral classes) are studied by using STARLIGHT. Among the 4 spectral classes, the importance of young populations decreases from star-forming, composite, Seyfert 2 to LINER; and Seyfert 2 and LINER are more metal-rich; ULIGs (ultra luminous infrared galaxies) & LIGs present the youngest populations among 3 infrared luminosity bins; and normal galaxies are more metal-rich. The dominant contributors to mas

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Rulten, Cameron B., Anthony M. Brown, and Paula M. Chadwick. "A search for Centaurus A-like features in the spectra of Fermi-LAT detected radio galaxies." Monthly Notices of the Royal Astronomical Society 492, no. 4 (2020): 4666–79. http://dx.doi.org/10.1093/mnras/staa054.

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ABSTRACT Motivated by the detection of a hardening in the γ-ray spectrum of the radio galaxy Centaurus A, we have analysed $\mathord {\sim }10$ yr of Fermi-Large Area Telescope (LAT) observations of 26 radio galaxies to search for similar spectral features. We find that the majority of the radio galaxies’ γ-ray spectral energy distributions are best fitted with a simple power-law model, and no spectral hardening similar to that found in Centaurus A was detected. We show that, had there been any such spectral features present in our sample of radio galaxies, they would have been seen, but note

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15

Inoue, H. "X-Ray Spectral Properties of Radio Galaxies." Symposium - International Astronomical Union 175 (1996): 273–76. http://dx.doi.org/10.1017/s0074180900080797.

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16

Peterson, B. M. "Spectral Variability in Seyfert Galaxies." Symposium - International Astronomical Union 121 (1987): 161–67. http://dx.doi.org/10.1017/s007418090015507x.

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Recent observations of spectral variability in active galactic nuclei have established the connection between the broad emission-line and optical continuum flux changes. The inferred size of the broad-line region is at least an order of magnitude smaller than conventional estimates based on photoionization models, which leads to new conclusions about the nature of the broad-line region.

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Shahzamanian, Banafsheh, Sadollah Nasiri, and Sepehr Arbabi. "Spectral Evolution of Field Galaxies." Journal of Physics: Conference Series 372 (July 30, 2012): 012072. http://dx.doi.org/10.1088/1742-6596/372/1/012072.

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Bizyaev, Dmitry, D. I. Makarov, V. P. Reshetnikov, A. V. Mosenkov, S. J. Kautsch, and A. V. Antipova. "Spectral Observations of Superthin Galaxies." Astrophysical Journal 914, no. 2 (2021): 104. http://dx.doi.org/10.3847/1538-4357/abfb03.

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Sodré, L., A. Mateus, R. Cid Fernandes, G. Stasińska, W. Schoenell, and J. M. Gomes. "The Bimodality of Galaxy Populations Revisited Through Spectral Synthesis." Proceedings of the International Astronomical Union 2, S235 (2006): 139. http://dx.doi.org/10.1017/s1743921306005710.

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AbstractWe revisit the bimodality of the galaxy population seen in the local universe. We address this issue in terms of physical properties of galaxies, such as mean stellar ages and stellar masses, derived from the application of a spectral synthesis method to galaxy spectra from the SDSS. We show that the mean light-weighted stellar age of galaxies presents the best description of the bimodality seen in the galaxy population. The stellar mass has an additional role since most of the star-forming galaxies present in the local universe are low-mass galaxies. Our results give support to the ex

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Simpemba, Prospery. "Spectral energy distribution of blazars." Proceedings of the International Astronomical Union 15, S356 (2019): 374. http://dx.doi.org/10.1017/s1743921320003464.

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AbstractThis study focuses on spectral energy distributions and light-curves of blazars and radio galaxies, and the testing of the existing models with a view to appropriately predict a new model that will nearly accurately present the nature of the energy outflows of these super-massive bodies. Understanding blazar emission is very important as it relates more directly to the physics of the AGN’s central black hole. X-ray, radio and gamma-ray wavelength range data on blazars and radio galaxies from archived data has been collected and a detailed investigation of the spectral energy distributi

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Ciesla, Laure. "The spectral energy distributions of the entire Herschel Reference Survey." Proceedings of the International Astronomical Union 7, S284 (2011): 283–85. http://dx.doi.org/10.1017/s1743921312009258.

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AbstractWe present the spectral energy distributions (SED) of the 323 galaxies of the Herschel Reference Survey. In order to provide templates for nearby galaxies calibrated on physical parameters, we computed mean SEDs per bin of morphological types and stellar masses. They will be very useful to study more distant galaxies and their evolution with redshift. This preliminary work aims to study how the most commonly used libraries (Chary & Elbaz 2001, Dale & Helou 2002 and Draine & Li 2007) reproduce the far-infrared emission of galaxies. First results show that they reproduce well

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Glowacki, M., E. Elson, and R. Davé. "The redshift evolution of the baryonic Tully–Fisher relation in SIMBA." Monthly Notices of the Royal Astronomical Society 507, no. 3 (2021): 3267–84. http://dx.doi.org/10.1093/mnras/stab2279.

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ABSTRACT The baryonic Tully–Fisher relation (BTFR) is an important tool for constraining galaxy evolution models. As 21-cm H i emission studies have been largely restricted to low redshifts, the redshift evolution of the BTFR is less studied. The upcoming LADUMA survey (Looking At the Distant Universe with the MeerKAT Array) will address this. As preparation for LADUMA, we use the SIMBA hydrodynamical galaxy formation simulation from the SIMBA-hires $(25\, h^{-1}{\rm Mpc})^3$ run to generate rotational velocity measures from galaxy rotation curves (Vflat) and H i spectral line profile widths (

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Małek, K., A. Pollo, T. T. Takeuchi, V. Buat, D. Burgarella, and M. Malkan. "Dust in FIR-bright ADF-S galaxies." Proceedings of the International Astronomical Union 10, S309 (2014): 325. http://dx.doi.org/10.1017/s1743921314010205.

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AbstractMultiwavelength Spectral Energy Distributions (SEDs) of far-infrared (FIR) galaxies detected in the AKARI South Ecliptic Poles Survey (ADF-S) allow to trace differences between [Ultra]-Luminous Infrared Galaxies ([U]LIRGS) and other types of star-forming galaxies (SF).

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Chyży, K. T., W. Jurusik, J. Piotrowska, et al. "LOFAR MSSS: Flattening low-frequency radio continuum spectra of nearby galaxies." Astronomy & Astrophysics 619 (November 2018): A36. http://dx.doi.org/10.1051/0004-6361/201833133.

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Aims. The shape of low-frequency radio continuum spectra of normal galaxies is not well understood, the key question being the role of physical processes such as thermal absorption in shaping them. In this work we take advantage of the LOFAR Multifrequency Snapshot Sky Survey (MSSS) to investigate such spectra for a large sample of nearby star-forming galaxies. Methods. Using the measured 150 MHz flux densities from the LOFAR MSSS survey and literature flux densities at various frequencies we have obtained integrated radio spectra for 106 galaxies characterised by different morphology and star

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François, P., L. Morelli, A. Pizzella, et al. "Near-infrared spectroscopic indices for unresolved stellar populations." Astronomy & Astrophysics 621 (January 2019): A60. http://dx.doi.org/10.1051/0004-6361/201833956.

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Context. A new generation of spectral synthesis models has been developed in recent years, but there is no matching set of template galaxy spectra, in terms of quality and resolution, for testing and refining the new models. Aims. Our main goal is to find and calibrate new near-infrared spectral indices along the Hubble sequence of galaxies which will be used to obtain additional constraints to the population analysis based on medium-resolution integrated spectra of galaxies. Methods. Spectra of previously studied and well-understood galaxies with relatively simple stellar populations (e.g., e

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Karachentsev, Igor D., Valentina E. Karachentseva, Walter K. Huchtmeier, Dmitry I. Makarov, and Serafim S. Kaisin. "Probe of Dark Galaxies via Disturbed/Lopsided Isolated Galaxies." Proceedings of the International Astronomical Union 3, S244 (2007): 235–46. http://dx.doi.org/10.1017/s1743921307014044.

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AbstractSearching for lopsided/interacting objects among 1500 isolated galaxies yields only eight strongly disturbed galaxies which may be explained as a result of their interaction with massive dark objects. We present results of spectral and photometric observations of these galaxies performed with the 6-m telescope that lead to significant restriction on cosmic abundance of dark galaxies.

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Mordini, Sabrina, Luigi Spinoglio, and Juan Antonio Fernández-Ontiveros. "Calibration of mid- to far-infrared spectral lines in galaxies." Astronomy & Astrophysics 653 (September 2021): A36. http://dx.doi.org/10.1051/0004-6361/202140696.

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Context. Mid- to far-infrared (IR) lines are suitable in the study of dust-obscured regions in galaxies because dust extinction strongly decreases with wavelength, and therefore IR spectroscopy allows us to explore the most hidden regions of galaxies, where heavily obscured star formation as well as accretion onto supermassive black holes at the nuclei of galaxies occur. This is mostly important for the so-called cosmic noon (i.e. at redshifts of 1 < z < 3), at which point most of the baryonic mass in galaxies has been assembled. Aims. Our goal is to provide reliable calibrations of the

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Wu, H., Z. L. Zou, X. Y. Xia, and Z. G. Deng. "Evolution of Very Luminous Infrared Galaxies." Symposium - International Astronomical Union 186 (1999): 364. http://dx.doi.org/10.1017/s0074180900113117.

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We have completed spectroscopic observations (Wu et al. 1997a) of a sample of 73 very luminous infrared galaxies (log(LIR/L⊙) ≥ 11.5;H0 = 50 km s−1 Mpc−1) from the 2-Jy catalogue (Strauss et al. 1992) using the 2.16m telescope at the Beijing Astronomical Observatory. Spectral and interacting classifications are performed for the sample (Wu et al. 1997b). These statistical results provide strong evidence for the idea that interactions trigger nuclear activity and enhance the infrared luminosity. With the decrease of nuclear separation, relative velocity and specific angular momentum decrease ra

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Clerici, Slodkowski Katia, and Natalia Vale Asari. "Direct measures of chemical abundances from stacked spectra of star-forming galaxies: Implications for the mass–metallicity–star formation rate relation." Proceedings of the International Astronomical Union 15, S359 (2020): 424–26. http://dx.doi.org/10.1017/s174392132000188x.

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AbstractThe stellar mass–star formation rate–metallicity relation provides clues on the chemical evolution of galaxies. We revisit this relation by measuring the gas-phase metallicity using the direct method. For metal-rich galaxies this is not straightforward, because auroral emission lines sensitive the electron temperature are lost in spectral noise. In order to increase the spectral signal-to-noise ratio and detect faint auroral lines, we stack the spectra of similar galaxies. This allows us to use the direct method to obtain consistent metallicity measurements.

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Schaerer, Daniel, Frederic Boone, and Nicolas Laporte. "The unusual multi-wavelength SED of two optical dropout galaxies." Proceedings of the International Astronomical Union 7, S284 (2011): 315–16. http://dx.doi.org/10.1017/s1743921312009349.

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AbstractWe have used deep optical, near-IR, and IR observations from VLT, Spitzer, Herschel, and LABOCA in strong lensing clusters to study distant galaxies. In searches for optical-dropout galaxies (i.e. for z ≳ 7 candidates) we have found several galaxies with very unusual SEDs characterised by a strong spectral break, presumably indicative of high-z, although the objects are detected even in the Herschel bands between 160 and 500 μm and at 870 μm. The latter indicates, from simple estimates of the bolometric luminosity and from the IR SED, that these ob jects are most likely at z ~ 2–2.5.Th

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Svensson, R. "X/γ-rays from Active Galactic Nuclei". Symposium - International Astronomical Union 195 (2000): 143–52. http://dx.doi.org/10.1017/s0074180900162886.

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Recent progress using RXTE and BeppoSAX to study the X/γ emission from radio-quiet active galactic nuclei, i.e., Seyfert galaxies, is reviewed. These satellites allow simultaneous broad-band spectra extending from 0.1–200 keV to be observed for the first time and allow the various spectral components to be determined with some certainty. In particular, the new observations support the unified model of Seyfert galaxies. Most importantly, it has been found that a large fraction of Seyfert 2 galaxies have Compton-thick tori surrounding their nuclei. Spectral transitions in Seyfert galaxies are di

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Fritz, Jacopo, Bianca M. Poggianti, Antonio Cava, and Alessia Moretti. "Equivalent width Measurements in Optical Spectra of Galaxies in Local Clusters: Hints On the Star Formation History in Clusters." Open Astronomy 20, no. 3 (2011): 435–41. http://dx.doi.org/10.1515/astro-2017-0315.

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Abstract Equivalent widths of spectral lines in the optical spectra of galaxies are commonly used to characterize their stellar populations and to get some insight on their evolution. Here we describe a new method to measure automatically equivalent widths of spectral lines with a good accuracy. This makes possible to classify galaxies according to the presence/absence and intensity of [O II] and Hδ lines. Based on these classification criteria, we give a description of the characteristics of the star-forming and post-starburst galaxies in local clusters, and their dependence on the cluster ch

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Torres-Papaqui, J. P., R. Coziol, and R. A. Ortega-Minakata. "The Chemical Evolution of Narrow Emission Line Galaxies: the Key to their Formation Processes." Acta Universitaria 21 (September 1, 2011): 82–91. http://dx.doi.org/10.15174/au.2011.39.

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Using the largest sample of narrow emission line galaxies available so far, we show that their spectral characteristics are correlated with different physical parameters, like the chemical abundances, the morphologies, the masses of the bulge and the mean stellar age of the stellar populations of the host galaxies. It suggests that the spectral variations observed in standard spectroscopic diagnostic diagrams are not due solely to variations of ionization parameters or structures but reflect also the chemical evolution of the galaxies, which in turn can be explained by different galaxy formati

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Stepanian, J. A., L. K. Erastova, V. A. Lipovetsky, and A. I. Shapovalova. "The Second Byurakan Spectral Sky Survey, Quasistellar Objects and Seyfert Galaxies." Symposium - International Astronomical Union 134 (1989): 31–34. http://dx.doi.org/10.1017/s0074180900140264.

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Survey of surveys, and the place of the Second Byurakan Survey (SBS) among them is shortly discussed. Deep low-dispersion surveys cover > 10000 sq.degrees, but they managed to study only 15% of this area relatively well.For 450 SBS objects the slit spectra were obtained on 6 m telescope of SAO. The nature of 120 QS0s,40 Sy galaxies and more than 200 ELG are confirmed. The results of the slit spectroscopy in six SBS fields covering commonly the area of ∼100 sq.degrees are presented.All surveys, except Byurakan Surveys are extremely poor with Sy galaxies, that is their distinction from other

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Guo, Xiaotong, Qiusheng Gu, Nan Ding, E. Contini, and Yongyun Chen. "Physical properties of the CDFS X-ray sources through fitting spectral energy distributions." Monthly Notices of the Royal Astronomical Society 492, no. 2 (2019): 1887–901. http://dx.doi.org/10.1093/mnras/stz3589.

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ABSTRACT The physical parameters of galaxies and/or active galactic nucleus (AGNs) can be derived by fitting their multiband spectral energy distributions (SEDs). By using cigale code, we perform multiband SED fitting (from ultraviolet to infrared) for 791 X-ray sources (518 AGNs and 273 normal galaxies) in the 7 Ms Chandra Deep Field-south survey (CDFS). We consider the contributions from AGNs and adopt more accurate redshifts than published before. Therefore, more accurate star formation rates (SFRs) and stellar masses (M*) are derived. We classify the 518 AGNs into type-I and type-II based

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Osterbrock, Donald E. "Seyfert Galaxies: Classification, Morphology, Observations at Optical Wavelengths, Environmental Factors." Symposium - International Astronomical Union 121 (1987): 109–18. http://dx.doi.org/10.1017/s0074180900154993.

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Recent optical work on Seyfert galaxies is summarized, particularly on their spectral classification, morphology, companions, and presence in clusters of galaxies. Their general continuity with QSOs and with Liners is emphasized. Methods of finding additional Seyfert galaxies and of assembling a complete sample for investigating the luminosity function of AGNs are also discussed.

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Thomas, R., O. Le Fèvre, G. Zamorani, et al. "The most massive, passive, and oldest galaxies at 0.5 < z < 2.1: Downsizing signature from galaxies selected from MgUV index." Astronomy & Astrophysics 630 (October 2019): A145. http://dx.doi.org/10.1051/0004-6361/201935813.

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Aims. We seek is to identify old and massive galaxies at 0.5 < z < 2.1 on the basis of the magnesium index MgUV and then study their physical properties. Methods. We computed the MgUV index based on the best spectral fitting template of ∼3700 galaxies using data from the VLT VIMOS Deep Survey (VVDS) and VIMOS Ultra Deep Survey (VUDS) galaxy redshift surveys. Based on galaxies with the largest signal to noise and the best fit spectra we selected 103 objects with the highest spectral MgUV signature. We performed an independent fit of the photometric data of these galaxies and computed thei

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da Cunha, Elisabete, Stéphane Charlot, and David Elbaz. "A simple model to interpret the ultraviolet, optical and infrared SEDs of galaxies." Proceedings of the International Astronomical Union 5, S262 (2009): 81–84. http://dx.doi.org/10.1017/s1743921310002565.

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AbstractWe present a simple, largely empirical but physically motivated model, which is designed to interpret consistently multi-wavelength observations from large samples of galaxies in terms of physical parameters, such as star formation rate, stellar mass and dust content. Our model is both simple and versatile enough to allow the derivation of statistical constraints on the star formation histories and dust contents of large samples of galaxies using a wide range of ultraviolet, optical and infrared observations. We illustrate this by deriving median-likelihood estimates of a set of physic

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Han, Yunkun, Zhanwen Han, and Lulu Fan. "Bayesian discrimination of the panchromatic spectral energy distribution modelings of galaxies." Proceedings of the International Astronomical Union 15, S341 (2019): 143–46. http://dx.doi.org/10.1017/s1743921319002746.

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AbstractFitting the multi-wavelength spectral energy distributions (SEDs) of galaxies is a widely used technique to extract information about the physical properties of galaxies. However, a major difficulty lies in the numerous uncertainties regarding almost all ingredients of the SED modeling of galaxies. The Bayesian methods provide a consistent conceptual basis for dealing with the problem of inference with many uncertainties. While the Bayesian parameter estimation method have become quite popular in the field of SED fitting of galaxies, the Bayesian model comparison method, which is based

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Sturm, E., D. Lutz, and R. Genzel. "A Survey of Spectral Features in ISO SWS Spectra of AGNs." International Astronomical Union Colloquium 159 (1997): 337–38. http://dx.doi.org/10.1017/s0252921100040380.

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Various AGNs, starburst galaxies, and ultraluminous infrared galaxies (ULIRGs) are observed as part of the ISO-SWS central program of mid-infrared spectroscopy on bright galactic nuclei. Prototypical template sources are scanned over the full spectral range of SWS (2.5–45µm) in order to get a complete census of spectral features in this wavelength domain. As an example we present the spectrum of the Seyfert 2 galaxy Circinus. The application of results from this survey to the study of the nature and evolution of other galaxies can be demonstrated by an analysis of the ultraluminous infrared ga

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Takagi, Toshinobu, Vladas Vansevičius, and Nobuo Arimoto. "Spectral Energy Distributions of Dusty Galaxies." Publications of the Astronomical Society of Japan 55, no. 2 (2003): 385–407. http://dx.doi.org/10.1093/pasj/55.2.385.

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Osterbrock, D. E., and S. Veilleux. "Spectral Classification of Emission-Line Galaxies." Publications of the Astronomical Society of the Pacific 98 (November 1986): 1106. http://dx.doi.org/10.1086/131945.

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Veilleux, Sylvain, and Donald E. Osterbrock. "Spectral classification of emission-line galaxies." Astrophysical Journal Supplement Series 63 (February 1987): 295. http://dx.doi.org/10.1086/191166.

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Bennert, N., H. Schulz, and C. Henkel. "Spectral characteristics of water megamaser galaxies." Astronomy & Astrophysics 419, no. 1 (2004): 127–37. http://dx.doi.org/10.1051/0004-6361:20034497.

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Schmidt, E. O., D. Ferreiro, L. Vega Neme, and G. A. Oio. "Spectral nuclear properties of NLS1 galaxies." Astronomy & Astrophysics 596 (December 2016): A95. http://dx.doi.org/10.1051/0004-6361/201629343.

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Lisker, T., K. Glatt, P. Westera, and E. K. Grebel. "The Last Stages of Star Formation in dEs?" Proceedings of the International Astronomical Union 2, S235 (2006): 317. http://dx.doi.org/10.1017/s174392130600682x.

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AbstractA significant fraction of Virgo cluster early-type dwarf galaxies have blue central colours caused by recent or ongoing star formation. A spectral analysis shows that even in their centers, stellar mass is dominated by an old population. These galaxies are an unrelaxed cluster population that possibly formed from morphological transformation of late-type galaxies.

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Leitherer, Claus. "Spectral Evolution Models for the Next Decade." Proceedings of the International Astronomical Union 5, S262 (2009): 73–80. http://dx.doi.org/10.1017/s1743921310002553.

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AbstractSpectral evolution models are a widely used tool for determining the stellar content of galaxies. I provide a review of the latest developments in stellar atmosphere and evolution models, with an emphasis on massive stars. In contrast to the situation for low- and intermediate-mass stars, the current main challenge for spectral synthesis models are the uncertainties and rapid revision of current stellar evolution models. Spectral libraries, in particular those drawn from theoretical model atmospheres for hot stars, are relatively mature and can complement empirical templates for larger

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Gomes, Jean Michel, та Paula Coelho. "Spectral fitting of SDSS passive galaxies with α-enhanced single stellar populations". Proceedings of the International Astronomical Union 7, S284 (2011): 66–68. http://dx.doi.org/10.1017/s1743921312008769.

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AbstractThe power of population synthesis as a mean to estimate the star-formation and chemical histories of galaxies has been well established in the last decade. The major developments were due to a huge avalanche of methods, codes and high-quality galaxy data sets, such as the 2dF, 6dF and SDSS surveys. Semi-empirical spectral synthesis allows for the decomposition of a galaxy spectrum in terms of linear combinations of base elements, i.e. Single Stellar Populations (SSPs) of different ages and metallicities, which are computed from evolutionary synthesis codes (BPASS, GALEV, GALAXEV, MILES

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Dressler, Alan, and James E. Gunn. "Observational Evidence for Spectral Evolution of Cluster Galaxies." Symposium - International Astronomical Union 130 (1988): 311–19. http://dx.doi.org/10.1017/s0074180900136198.

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The study of galaxy evolution with large lookback times is dominated by two difficult issues. The first is a technical matter. Even the most luminous galaxies are faint (mr < 19) at significant lookback times (z ≳ 0.5), and so spectrophotometric observations of average galaxies challenge our present telescope and detector technology. The second issue is the selection of objects in an unbiased way in order to assemble a representative sample of galaxies at the remote epoch. It is far too easy to chase only exotic objects whose very peculiarity has brought them to our attention. Though observ

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Connolly, A. J., and A. S. Szalay. "An Objective Approach to Spectral Classification." Symposium - International Astronomical Union 179 (1998): 376–78. http://dx.doi.org/10.1017/s0074180900129079.

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The next generation of spectroscopic surveys, both Galactic and extra-galactic (e.g., SDSS, 2dF), present the challenge of classifying spectra in an efficient and objective manner. The standard approach to this problem has been to visually classify spectra based on a number of spectral features (e.g., the equivalent widths of emission lines). The size of new spectral surveys (> 106 galaxies) and the desire to compare the luminosity and environments of galaxies with their spectral properties make these techniques infeasible. We describe here an automated classification scheme that is being d

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