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2. Spectral energy distributions of hard X-ray selected active galactic nuclei in the XMM-Newton Medium Deep Survey

Author

Polletta, M., Tajer, M., Maraschi, L., Trinchieri, G., Lonsdale, C. J., Chiappetti, L., Andreon, S., Pierre, M., Le Fèvre, O., Zamorani, G., Maccagni, D., Garcet, O., Surdej, J., Franceschini, A., Alloin, D., Shupe, D. L., Surace, J. A., Fang, F., Rowan-Robinson, M., Smith, H. E., and Tresse, L.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We present the SEDs of a hard X-ray selected sample containing 136 sources with F_(2-10 keV) > 10^(-14) erg cm^(-2) s^(-1); 132 are AGNs. The sources are detected in a 1 deg^2 area of the XMM-Newton Medium Deep Survey where optical data from the VVDS and CFHTLS and infrared data from the SWIRE survey are available. Based on a SED fitting technique we derive photometric redshifts with σ(1 + z) = 0.11 and 6% of outliers and identify AGN signatures in 83% of the objects. This fraction is higher than derived when a spectroscopic classification is available. The remaining 17^(+9)_(-6)% of AGNs show star-forming galaxy SEDs (SF class). The sources with AGN signatures are divided in two classes, AGN1 (33^(+6)_(-1)%) and AGN2 (50^(+6)_(-11)%). The AGN1 and AGN2 classes include sources whose SEDs are fitted by type 1 and type 2 AGN templates, respectively. On average, AGN1s show soft X-ray spectra, consistent with being unabsorbed, while AGN2s and SFs show hard X-ray spectra, consistent with being absorbed. The analysis of the average SEDs as a function of X-ray luminosity shows a reddening of the infrared SEDs, consistent with a decreasing contribution from the host galaxy at higher luminosities. The AGNs in the SF classes are likely obscured in the mid-infrared, as suggested by their low L_(3-20 μm)/L^(corr)_(0.5-10 keV) ratios. We confirm the previously found correlation for AGNs between the radio luminosity and the X-ray and the mid-infrared luminosities. The X-ray-radio correlation can be used to identify heavily absorbed AGNs. However, the estimated radio fluxes for the missing AGN population responsible for the bulk of the background at E > 10 keV are too faint to be detected even in the deepest current radio surveys.

Published
2007

3. The XMM-LSS survey: the Class 1 cluster sample over the initial 5 square degrees and its cosmological modelling

Author

Pacaud, F., Pierre, M., Adami, C., Altieri, B., Andreon, S., Chiappetti, L., Detal, A., Duc, P. -A., Galaz, G., Gueguen, A., Fèvre, J. -P. Le, Hertling, G., Libbrecht, C., Melin, J. -B., Ponman, T. J., Quintana, H., Refregier, A., Sprimont, P. -G., Surdej, J., Valtchanov, I., Willis, J. P., Alloin, D., Birkinshaw, M., Bremer, M. N., Garcet, O., Jean, C., Jones, L. R., Fèvre, O. Le, Maccagni, D., Mazure, A., Proust, D., Röttgering, H. J. A., Trinchieri, G., Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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), INAF - Osservatorio Astronomico di Brera (OAB), Istituto Nazionale di Astrofisica (INAF), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Departamento de Astronomía y Astrofísica [Santiago], Pontificia Universidad Católica de Chile (UC), and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES)

Subjects
[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics
Abstract

We present a sample of 29 galaxy clusters from the XMM-LSS survey over an area of some 5deg2 out to a redshift of z=1.05. The sample clusters, which represent about half of the X-ray clusters identified in the region, follow well defined X-ray selection criteria and are all spectroscopically confirmed. For all clusters, we provide X-ray luminosities and temperatures as well as masses. The cluster distribution peaks around z=0.3 and T =1.5 keV, half of the objects being groups with a temperature below 2 keV. Our L-T(z) relation points toward self-similar evolution, but does not exclude other physically plausible models. Assuming that cluster scaling laws follow self-similar evolution, our number density estimates up to z=1 are compatible with the predictions of the concordance cosmology and with the findings of previous ROSAT surveys. Our well monitored selection function allowed us to demonstrate that the inclusion of selection effects is essential for the correct determination of the evolution of the L-T relation, which may explain the contradictory results from previous studies. Extensive simulations show that extending the survey area to 10deg2 has the potential to exclude the non-evolution hypothesis, but that constraints on more refined ICM models will probably be limited by the large intrinsic dispersion of the L-T relation. We further demonstrate that increasing the dispersion in the scaling laws increases the number of detectable clusters, hence generating further degeneracy [in addition to sigma8, Omega_m, L(M,z) and T(M,z)] in the cosmological interpretation of the cluster number counts. We provide useful empirical formulae for the cluster mass-flux and mass-count-rate relations as well as a comparison between the XMM-LSS mass sensitivity and that of forthcoming SZ surveys., Comment: Accepted for publication by MNRAS. Full resolution images as well as additional cluster data are available through a dedicated database at http://l3sdb.in2p3.fr:8080/l3sdb/

Published
2007
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4. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. IX. Ultraviolet observations of fairall

Author

Rodríguez-Pascual, PM, Alloin, D, Clavel, J, Crenshaw, DM, Horne, K, Kriss, GA, Krolik, JH, Malkan, MA, Netzer, H, O'Brien, PT, Peterson, BM, Reichert, GA, Wamsteker, W, Alexander, T, Barr, P, Blandford, RD, Bregman, JN, Carone, TE, Clements, S, Courvoisier, TJ, De Robertis, MM, Dietrich, M, Dottori, H, Edelson, RA, Filippenko, AV, Gaskell, CM, Huchra, JP, Hutchings, JB, Kollatschny, W, Koratkar, AP, Korista, KT, Laor, A, MacAlpine, GM, Martin, PG, Maoz, D, McCollum, B, Morris, SL, Perola, GC, Pogge, RW, Ptak, RL, Recondo-González, MC, Rodríguez-Espinoza, JM, Rokaki, EL, Santos-Lleó, M, Sekiguchi, K, Shull, JM, Snijders, MAJ, Sparke, LS, Stirpe, GM, Stoner, RE, Sun, WH, Wagner, SJ, Wanders, I, Wilkes, BJ, Winge, C, and Zheng, W

Subjects
Molecular, active, Astronomy & Astrophysics, Atomic, Physical Chemistry, Particle and Plasma Physics, astro-ph, galaxies, Seyfert, ultraviolet, Nuclear, individual, Astronomical and Space Sciences, Physical Chemistry (incl. Structural)
Abstract

An 8 month monitoring campaign on the Seyfert 1 galaxy Fairall 9 has been conducted with the International Ultraviolet Explorer in an attempt to obtain reliable estimates of continuum-continuum and continuum-emission-line delays for a high-luminosity active galactic nucleus (AGN). While the results of this campaign are more ambiguous than those of previous monitoring campaigns on lower luminosity sources, we find general agreement with the earlier results: (1) there is no measurable lag between ultraviolet continuum bands, and (2) the measured emission-line time lags are very short. It is especially notable that the Lyα + N v emission-line lag is about 1 order of magnitude smaller than determined from a previous campaign by Clavel, Wamsteker, & Glass (1989) when Fairall 9 was in a more luminous state. In other well-monitored sources, specifically NGC 5548 and NGC 3783, the highest ionization lines are found to respond to continuum variations more rapidly than the lower ionization lines, which suggests a radially ionization-stratified broad-line region. In this case, the results are less certain, since none of the emission-line lags are very well determined. The best-determined emission line lag is Lyα + N v, for which we find that the centroid of the continuum-emission-line cross-correlation function is τcent ≈ 14-20 days. We measure a lag τcent ≲ 4 days for He II λ1640; this result is consistent with the ionization-stratification pattern seen in lower luminosity sources, but the relatively large uncertainties in the emission-line lags measured here cannot rule out similar lags for Lyα + N v and He II λ1640 at a high level of significance. We are unable to determine a reliable lag for C IV λ1550, but we note that the profiles of the variable parts of Lyα and C IV λ1550 are not the same, which does not support the hypothesis that the strongest variations in these two lines arise in the same region.

Published
1997

5. STEPS TOWARD DETERMINATION OF THE SIZE AND STRUCTURE OF THE BROAD-LINE REGION IN ACTIVE GALACTIC NUCLEI .8. AN INTENSIVE HST, IUE, AND GROUND-BASED STUDY OF NGC-5548

Author

KORISTA, K, ALLOIN, D, BARR, P, CLAVEL, J, COHEN, R, CRENSHAW, D, EVANS, I, HORNE, K, KORATKAR, A, KRISS, G, KROLIK, J, MALKAN, M, MORRIS, S, NETZER, H, OBRIEN, P, PETERSON, B, REICHERT, G, RODRIGUEZPASCUAL, P, WAMSTEKER, W, ANDERSON, K, AXON, D, BENITEZ, E, BERLIND, P, BERTRAM, R, BLACKWELL, J, BOCHKAREV, N, BOISSON, C, CARINI, M, CARRILLO, R, CARONE, T, CHENG, F, CHRISTENSEN, J, CHUVAEV, K, DIERICH, M, DOKTER, J, DOROSHENKO, V, DULTZINHACYAN, D, ENGLAND, M, ESPEY, B, FILIPPENKO, A, GASKELL, C, GOAD, M, HO, L, HUCHRA, J, JIANG, X, KASPI, S, KOLLATSCHNY, W, LAOR, A, LUMINET, J, MACALPINE, G, MACKENTY, J, MALKOV, Y, MAOZ, D, MARTIN, P, MATHESON, T, MCCOLLUM, B, MERKULOVA, N, METIK, L, MIGNOLI, M, MILLER, H, PASTORIZA, M, PELAT, D, PENFOLD, J, PEREZ, M, PEROLA, G, PERSAUD, J, PETERS, J, PITTS, R, POGGE, R, PRONIK, I, PRONIK, V, PTAK, R, RAWLEY, L, RECONDOGONZALEZ, M, RODRIGUEZESPINOSA, J, ROMANISHIN, W, SADUN, A, SALAMANCA, I, SANTOSLLEO, M, SEKIGUCHI, K, SERGEEV, S, SHAPOVALOVA, A, SHIELDS, J, SHRADER, C, SHULL, J, SILBERMANN, N, SITKO, M, SKILLMAN, D, SMITH, H, SMITH, S, SNIJDERS, M, SPARKE, L, STIRPE, G, STONER, R, SUN, W, THIELE, U, TOKARZ, S, TSVETANOV, Z, TURNSHEK, D, VEILLEUX, S, WAGNER, R, WAGNER, S, WANDERS, I, WANG, T, WELSH, W, WEYMANN, R, WHITE, R, WILKES, B, WILLS, B, WINGE, C, WU, H, and ZOU, Z

Published
1995

6. Monitoring of active galactic nuclei IV. The Seyfert 1 galaxy NGC 4593

Author

Dietrich, M., Kollatschny, W., Alloin, D., Aretxaga, I., Axon, D., Bruyn, A. G., Clavel, J., Michael Goad, Gondhalekar, P., Groningen, E., Horne, K., Jackson, N., Laurikainen, E., Lawrence, A., Masegosa, J., Moles, M., O Brien, P., Del Olmo, A., Penston, M. V., Perea, J., Pérez, E., Pérez-Fournon, I., Perry, J. J., Peterson, B. M., Robinson, A., Rodríguez Espinosa, J. M., Stirpe, G. M., Tadhunter, C., Terlevich, R., Unger, S., Wagner, S. J., Wanders, I., and Williams, R.

7. The Near-IR Luminosity-Metallicity Relationship for Dwarf Irregular Galaxies

Author

Ivo Saviane, Riegerbauer, R., Held, E. V., Ivanov, V., Alloin, D., Bresolin, F., Momany, Y., Rich, R. M., and Rizzi, L.

Subjects
Astrophysics (astro-ph), Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We briefly describe our on-going investigation of the near-IR luminosity-metallicity relationship for dwarf irregular galaxies in nearby groups of galaxies. The motivations of the project and the observational databases are introduced, and a preliminary result is presented. The 12+log(O/H) vs.H plane must be populated with more low-luminosity galaxies before a definite conclusion can be drawn., Comment: To be published in "Recycling intergalactic and interstellar matter", IAU Symposium Series, Vol. 217, 2004, Pierre-Alain Duc, Jonathan Braine and Elias Brinks, eds

8. The XMM Large Scale Structure Survey and its multi-λ follow-up

Author

Pierre, M., Alloin, D., Altieri, B., Mn, Bremer, Mark Birkinshaw, Bohringer, H., Hjorth, J., Jones, L., Le Fevre, O., Maccagni, D., Mcbreen, B., Mellier, Y., Molinari, E., Quintana, H., Rottgering, H., Surdej, J., Vigroux, L., White, S., and Lonsdale, C.

9. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. VIII. An intensive HST, IUE, and ground-based study of NGC 5548

Author

Korista, K. T., Alloin, D., Barr, P., Clavel, J., Cohen, R. D., Crenshaw, D. M., Evans, I. N., Horne, K., Koratkar, A. P., Kriss, G. A., Krolik, J. H., Malkan, M. A., Morris, S. L., Netzer, H., O Brien, P. T., Peterson, B. M., Reichert, G. A., Rodríguez-Pascual, P. M., Wamsteker, W., Anderson, K. S. J., Axon, D. J., Benitez, E., Berlind, P., Bertram, R., Blackwell Jr, J. H., Bochkarev, N. G., Boisson, C., Carini, M., Carrillo, R., Carone, T. E., Cheng, F. -Z, Christensen, J. A., Chuvaev, K. K., Dietrich, M., Dokter, J. J., Doroshenko, V., Dultzin-Hacyan, D., England, M. N., Brian Espey, Filippenko, A. V., Gaskell, C. M., Goad, M. R., Ho, L. C., Huchra, J. P., Jiang, X. J., Kaspi, S., Kollatschny, W., Laor, A., Luminet, J. -P, Macalpine, G. M., Mackenty, J. W., Malkov, Yu F., Maoz, D., Martin, P. G., Matheson, T., Mccollum, B., Merkulova, N., Metik, L., Mignoli, M., Miller, H. R., Pastoriza, M. G., Pelat, D., Penfold, J., Perez, M., Perola, G. C., Persaud, J. L., Peters, J., Pitts, R., Pogge, R. W., Pronik, I., Pronik, V. I., Ptak, R. L., Rawley, L., Recondo-González, M. C., Rodríguez-Espinosa, J. M., Romanishin, W., Sadun, A. C., Salamanca, I., Santos-Lleó, M., Sekiguchi, K., Sergeev, S. G., Shapovalova, A. I., Shields, J. C., Shrader, C., Shull, J. M., Silbermann, N. A., Sitko, M. L., Skillman, D. R., Smith, H. A., Smith, S. M., Snijders, M. A. J., Sparke, L. S., Stirpe, G. M., Stoner, R. E., Sun, W. -H, Thiele, U., Tokarz, S., Tsvetanov, Z. I., Turnshek, D. A., Veilleux, S., Wagner, R. M., Wagner, S. J., Wanders, I., Wang, T., Welsh, W. F., Weymann, R. J., White, R. J., Wilkes, B. J., Wills, B. J., Winge, C., Wu, H., and Zou, Z. L.

12. The XMM-LSS Cluster Sample and its Cosmological Applications

Author

Pierre, M., Pacaud, F., Adami, C., Altieri, B., Andreon, S., Lucio Chiappetti, Detal, A., Duc, P. -A, Galaz, G., Gueguen, A., Le Fèvre, J. -P, Hertling, G., Libbrecht, C., Melin, J. -B, Ponman, T. J., Quintana, H., Refregier, A., Sprimont, P. -G, Surdej, J., Valtchanov, I., Willis, J. P., Alloin, D., Birkinshaw, M., Bremer, M. N., Garcet, O., Jean, C., Jones, L. R., Le Fèvre, O., Maccagni, D., Mazure, A., Proust, D., Röttgering, H. J. A., and Trinchieri, G.

15. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. I. An 8 month campaign of monitoring NGC 5548 with IUE

Author

Clavel, J., Reichert, G. A., Alloin, D., Crenshaw, D. M., Kriss, G., Krolik, J. H., Malkan, M. A., Netzer, H., Peterson, B. M., Wamsteker, W., Altamore, A., Baribaud, T., Barr, P., Beck, S., Luc Binette, Bromage, G. E., Brosch, N., Diaz, A. I., Filippenko, A. V., Fricke, K., Gaskell, C. M., Giommi, P., Glass, I. S., Gondhalekar, P., Hackney, R. L., Halpern, J. P., Hutter, D. J., Jörsäter, S., Kinney, A. L., Kollatschny, W., Koratkar, A., Korista, K. T., Laor, A., Lasota, J. P., Leibowitz, E., Maoz, D., Martin, P. G., Mazeh, T., Meurs, E. J. A., Nair, A. D., O Brien, P., Pelat, D., Perez, E., Perola, G. C., Ptak, R. L., Rodriguez-Pascual, P., Rosenblatt, E. I., Sadun, A. C., Santos-Lleo, M., Shaw, R. A., Smith, P. S., Stirpe, G. M., Stoner, R., Sun, W. H., Ulrich, M. -H, Groningen, E., and Zheng, W.

Subjects
Galaxies: individual (NGC 5548), Seyfert [Galaxies], Galaxies: Seyfert, spectra [Ultraviolet], individual (NGC 5548) [Galaxies], nuclei [Galaxies], Física, Ultraviolet: spectra, Galaxies: nuclei
Abstract

This is an electronic version of an article published in The Astrophysical Journal. Clavel, J. et al. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. I. An 8 month campaign of monitoring NGC 5548 with IUE. The Astrophysical Journal 366 (1991): 64-81

16. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. V. Variability of the ultraviolet continuum and emission lines of NGC 3783

Author

Reichert, G. A., Rodríguez-Pascual, P. M., Alloin, D., Clavel, J., Crenshaw, D. M., Kriss, G. A., Krolik, J. H., Malkan, M. A., Netzer, H., Peterson, B. M., Wamsteker, W., Altamore, A., Altieri, B., Anderson, K. S., Blackwell Jr, J. H., Boisson, C., Brosch, N., Carone, T. E., Dietrich, M., England, M. N., Evans, I. N., Filippenko, A. V., Gaskell, C. M., Goad, M., Gondhalekar, P. M., Horne, K., Kazanas, D., Kollatschny, W., Koratkar, A. P., Korista, K. T., Macalpine, G. M., Maoz, D., Mazeh, T., Mccollum, B., Miller, H. R., Mendes Oliveira, C., O Brien, P. T., Pastoriza, M. G., Pelat, D., Pérez, E., Perola, G. C., Pogge, R. W., Ptak, R. L., Recondo-González, M. C., Rodríguez-Espinosa, J., Rosenblatt, E. I., Sadun, A. C., Santos-Lléo, M., Shields, J. C., Shrader, C. R., Shull, J. M., Simkin, S. M., Sitko, M. L., Snijders, M. A. J., Sparke, L. S., Giovanna Maria Stirpe, Stoner, R., Storchi-Bergmann, T., Sun, W. -H, Wang, T., Welsh, W. F., White, R. J., Winge, C., and Zheng, W.

Subjects
Galáxia NGC 5548, Seyfert [Galaxies], active [Galaxies], nuclei [Galaxies], Espectros astronômicos, individual (NGC 3783) [Galaxies], Galaxias seyfert, Nucleo galatico, Galáxia NGC 3783, galaxies [Ultraviolet]
Abstract

We report on the results of intensive ultraviolet spectral monitoring of the Seyfert 1 galaxy NGC 3783. The nucleus of NGC 3783 was observed with the International Ultraviolet Explorer satellite on a regular basis for a total of 7 months, once every 4 days for the first 172 days and once every other day for the final 50 days. Significant variability was observed in both continuum and emission-line ftuxes. The light curves for the con­ tinuum ftuxes exhibited two well-defined local mínima or "dips," the first lasting

17. The extended narrow line region of NGC 4151 I. Emission line ratios and their implications

Author

Penston, M. V., Robinson, A., Alloin, D., Appenzeller, I., Aretxaga, I., Axon, D. J., Baribaud, T., Barthel, P., Baum, S. A., Boisson, C., Bruyn, A. G. D., Clavel, J., Colina, L., Dennefeld, M., Diaz, A., Dietrich, M., Durret, F., Dyson, J. E., Gondhalekar, P., Groningen, E. V., Jablonka, P., Jackson, N., Kollatschny, W., Laurikainen, E., Lawrence, A., Masegosa, J., Mchardy, I., Meurs, E. J. A., Miley, G., Moles, M., O Brien, P., O Dea, C., Olmo, A. D., Pedlar, A., Perea, J., Perez, E., Perez-Fournon, I., Perry, J., Pilbratt, G., Rees, M., Robson, I., Rodriguez-Pascua, P., Espinosa, J. M. R., Santos-Lleo, M., Schilizzi, R., Stasinska, G., Stirpe, G. M., Tadhunter, C., Terlevich, E., Terlevich, R., Unger, S., Vila-Vilaro, V., Jose M. Vilchez, Wagner, S. J., Ward, M. J., and Yates, G. J.

18. Unveiling the nature of the Cloverleaf lens-system: HST/NICMOS-2 observations

Author

Jean-Paul Kneib, Alloin, D., and Pelló, R.

Subjects
Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We present new elements in the identification of the lens-system producing the 4 images of the BAL quasar H1413+117, based on the recent HST/NICMOS-2/F160W observations. After a careful PSF subtraction of the 4 images of the quasar, the residual H image reveals the presence of a faint object (H~20.5) within the region enclosed by the 4 quasar images. This object corresponds to a single galaxy: the primary lens of the lens-system. We also identify the galaxies around the Cloverleaf which had been proposed to belong to a galaxy cluster/group at high redshift (Kneib et al 1998): the other component in the lens-system that provides the additional "external" shear. For these galaxies, we have derived a likely redshift based upon their R, I and H magnitudes. We find that most of them are consistent with belonging to a galaxy cluster/group with mean redshift =0.9 +/- 0.1. Furthermore we detect 2 very red objects (I-H~4): the faintest one has no observed optical (R and I) counterpart, while the brightest has a predicted redshift around z~2, and may be identified with one of the Cloverleaf absorbers. This gravitational-lens system constitutes an excellent target for IR imaging/spectroscopy with the new generation of 8m ground-based telescopes., Comment: Submitted to A&A letters

19. Monitoring of active galactic nuclei I. The quasars 1302-102 and 1217 + 023

Author

Jackson, N., O Brien, P. T., Michael Goad, Alloin, D., Axon, D. J., Bruyn, A. G., Clavel, J., Dietrich, M., Gondhalekar, P. M., Groningen, E., Kollatschny, W., Laurikainen, E., Lawrence, A., Mchardy, I. M., Penston, M. V., Pérez, E., Pérez-Fournon, I., Robinson, A., Stirpe, G. M., Tadhunter, C. N., Terlevich, R. J., and Wagner, S.

20. An Intensive HST, IUE, and Ground-Based Study of NGC 5548

Author

Korista, K. T., Alloin, D., Barr, P., Clavel, J., Cohen, R. D., Crenshaw, D. M., Evans, I. N., Horne, K., Koratkar, A. P., Kriss, G. A., Krolik, J. H., Malkan, M. A., Simon Morris, Netzer, H., O Brien, P. T., Peterson, B. M., Reichert, G. A., Rodriguez-Pascual, P. M., and Wamsteker, W.

21. Molecular Outflows in the R Coronae Australis Region

Author

Lewis Knee, Lidman, C., and Alloin, D.

Abstract

The low mass star forming region associated with the Corona Australis cloud hosts an embedded culture of young stellar objects (YSOs), many of which drive molecular outflows associated with shock-excited (HH-objct) emission-line objects. CO(1-0) mapping from the SEST and CO(3-2) mapping from JCMT are presented and analyzed in the context of identifying outflows and associating them with known YSOs and HH-objects. This region hosts far more molecular outflows than previously thought and resembles in some respects the "burst" of outflow activity associated with the star forming region NGC1333.

Published
2017
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22. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. 5: Variability of the ultraviolet continuum and emission lines of NGC 3783

Author

H. R. Miller, C. M. Gaskell, Alexei V. Filippenko, Hagai Netzer, M. A. J. Snijders, Gail A. Reichert, Joseph C. Shields, Aldo Altamore, E. I. Rosenblatt, S. M. Simkin, Kirk T. Korista, M. C. Recondo-Gonzalez, J. H. Blackwell, I. N. Evans, A. C. Sadun, Thaisa Storchi-Bergmann, Miriani Griselda Pastoriza, Chris Shrader, Claudia Winge, R. Stoner, P. M. Gondhalekar, M. A. Malkan, G. M. Stirpe, Tsevi Mazeh, G. C. Perola, Anuradha Koratkar, M. N. England, Tinggui Wang, T. E. Carone, B. McCollum, Bradley M. Peterson, Gerard A. Kriss, J. M. Shull, W. Zheng, Danielle Alloin, M. Santos-Lleo, Roger Ptak, Catherine Boisson, J. Clavel, Demos Kazanas, K. S. J. Anderson, Julian H. Krolik, Noah Brosch, C. Mendes de Oliveira, Richard W. Pogge, W. Wamsteker, D. M. Crenshaw, P. T. O'Brien, Gordon M. MacAlpine, J. M. Rodriguez-Espinoza, W. F. Welsh, M. Dietrich, D. Maoz, B. Altieri, M. R. Goad, Linda S. Sparke, Enrique Pérez, P. M. Rodriquez-Pascual, Wolfram Kollatschny, D. Pelat, Keith Horne, Wei-Hsin Sun, R. J. White, Michael L. Sitko, Reichert, Ga, Rodriguezpascual, Pm, Alloin, D, Clavel, J, Crenshaw, Dm, Kriss, Ga, Krolik, Jh, Malkan, Ma, Netzer, H, Peterson, Bm, Wamsteker, W, Altamore, Aldo, Altieri, B, Anderson, K, Blackwell, Jh, Boisson, C, Brosch, N, Carone, Te, Dietrich, M, England, Mn, Evans, In, Filippenko, Av, Gaskell, Cm, Goad, M, Gondhalekar, Pm, Horne, K, Kazanas, D, Kollatschny, W, Koratkar, Ap, Korista, Kt, Macalpine, Gm, Maoz, D, Mazeh, T, Mccollum, B, Miller, Hr, Deoliveira, Cm, Obrien, Pt, Pastoriza, Mg, Pelat, D, Perez, E, Perola, Gc, Pogge, Rw, Ptak, Rl, Recondogonzalez, Mc, Rodriguezespinosa, J, Rosenblatt, Ei, Sadun, Ac, Santoslleo, M, Shields, Jc, Shrader, Cr, Shull, Jm, Simkin, Sm, Sitko, Ml, Snijders, Maj, Sparke, L, Stirpe, Gm, Stoner, R, Storchibergmann, T, Sun, Wh, Wang, T, Welsh, Wf, White, Rj, Winge, C, and Zheng, W.

Subjects
Physics, Active galactic nucleus, Astronomy, Doubly ionized oxygen, Astronomy and Astrophysics, Astrophysics, Light curve, Galaxy, Wavelength, Amplitude, Space and Planetary Science, Ionization, Emission spectrum
Abstract

We report on the results of intensive ultraviolet spectral monitoring of the Seyfert 1 galaxy NGC 3783. The nucleus of NGC 3783 was observed with the International Ultraviolet Explorer satellite on a regular basis for a total of 7 months, once every 4 days for the first 172 days and once every other day for the final 50 days. Significant variability was observed in both continuum and emission-line fluxes. The light curves for the continuum fluxes exhibited two well-defined local minima or 'dips,' the first lasting is less than or approximately 20 days and the second is less than or approximately 4 days, with additional episodes of relatively rapid flickering of approximately the same amplitude. As in the case of NGC 5548 (the only other Seyfert galaxy that has been the subject of such an intensive, sustained monitoring effort), the largest continuum variations were seen at the shortest wavelengths, so that the continuum became 'harder' when brighter. The variations in the continuum occurred simultaneously at all wavelengths (delta(t) is less than 2 days). Generally, the amplitude of variability of the emission lines was lower than (or comparable to) that of the continuum. Apart from Mg II (which varied little) and N V (which is relatively weak and badly blended with Ly(alpha), the light curves of the emission lines are very similar to the continuum light curves, in each case with a small systematic delay or 'lag.' As for NGC 5548, the highest ionization lines seem to respond with shorter lags than the lower ionization lines. The lags found for NGC 3783 are considerably shorter than those obtained for NGC 5548, with values of (formally) approximately 0 days for He II + O III), and approximately 4 days for Ly(alpha) and C IV. The data further suggest lags of approximately 4 days for Si IV + O IV) and 8-30 days for Si III + C III). Mg II lagged the 1460 A continuum by approximately 9 days, although this result depends on the method of measuring the line flux and may in fact be due to variability of the underlying Fe II lines. Correlation analysis further shows that the power density spectrum contains substantial unresolved power over timescales of is less than or approximately 2 days, and that the character of the continuum variability may change with time.

Published
1994

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