Relevant bibliographies by topics / AGN luminosity function

Academic literature on the topic 'AGN luminosity function'

Author: Grafiati
Published: 10 December 2022
Last updated: 29 January 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Contents

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'AGN luminosity function.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "AGN luminosity function"

1

Kulkarni, Girish, Gábor Worseck, and Joseph F. Hennawi. "Evolution of the AGN UV luminosity function from redshift 7.5." Monthly Notices of the Royal Astronomical Society 488, no. 1 (June 3, 2019): 1035–65. http://dx.doi.org/10.1093/mnras/stz1493.

Full text
Abstract:
ABSTRACTDeterminations of the ultraviolet (UV) luminosity function of active galactic nuclei (AGN) at high redshifts are important for constraining the AGN contribution to reionization and understanding the growth of supermassive black holes. Recent inferences of the luminosity function suffer from inconsistencies arising from inhomogeneous selection and analysis of data. We address this problem by constructing a sample of more than 80 000 colour-selected AGN from redshift $z$ = 0 to 7.5 using multiple data sets homogenized to identical cosmologies, intrinsic AGN spectra, and magnitude systems. Using this sample, we derive the AGN UV luminosity function from redshift $z$ = 0 to 7.5. The luminosity function has a double power-law form at all redshifts. The break magnitude M* shows a steep brightening from M* ∼ −24 at $z$ = 0.7 to M* ∼ −29 at $z$ = 6. The faint-end slope β significantly steepens from −1.9 at $z$ < 2.2 to −2.4 at $z$ ≃ 6. In spite of this steepening, the contribution of AGN to the hydrogen photoionization rate at $z$ ∼ 6 is subdominant (<3 per cent), although it can be non-negligible (∼10 per cent) if these luminosity functions hold down to M1450 = −18. Under reasonable assumptions, AGN can reionize He ii by redshift $z$ = 2.9. At low redshifts ($z$ < 0.5), AGN can produce about half of the hydrogen photoionization rate inferred from the statistics of H i absorption lines in the intergalactic medium. Our analysis also reveals important systematic errors in the data, which need to be addressed and incorporated in the AGN selection function in future in order to improve our results. We make various fitting functions, codes, and data publicly available.
APA, Harvard, Vancouver, ISO, and other styles
2

Merloni, Andrea, and Sebastian Heinz. "Cosmological evolution of the AGN kinetic luminosity function." Proceedings of the International Astronomical Union 2, S238 (August 2006): 65–70. http://dx.doi.org/10.1017/s174392130700470x.

Full text
Abstract:
AbstractWe present a first attempt to derive the cosmological evolution of the kinetic luminosity function of AGN based on the joint evolution of the flat spectrum radio and hard X-ray selected AGN luminosity functions. An empirical correlation between jet power and radio core luminosity is found, which is consistent with the theoretical assumption that, below a certain Eddington ratio, SMBH accrete in a radiatively inefficient way, while most of the energy output is in the form of kinetic energy.We show how the redshift evolution of the kinetic power density from such a low-ṁ mode of accretion makes it a good candidate to explain the so-called “radio mode” of AGN feedback as outlined in many galaxy formation schemes.
APA, Harvard, Vancouver, ISO, and other styles
3

Runburg, Jack, Duncan Farrah, Anna Sajina, Mark Lacy, Jenna Lidua, Evanthia Hatziminaoglou, W. N. Brandt, et al. "Consistent Analysis of the AGN LF in X-Ray and MIR in the XMM-LSS Field." Astrophysical Journal 924, no. 2 (January 1, 2022): 133. http://dx.doi.org/10.3847/1538-4357/ac37b8.

Full text
Abstract:
Abstract The luminosity function of active galactic nuclei (AGN) probes the history of supermassive black hole assembly and growth across cosmic time. To mitigate selection biases, we present a consistent analysis of the AGN luminosity functions (LFs) derived for both X-ray and mid-infrared (MIR) selected AGN in the XMM-Large Scale Structure field. There are 4268 AGN used to construct the MIR luminosity function (IRLF) and 3427 AGN used to construct the X-ray luminosity function (XLF), providing the largest census of the AGN population out to z = 4 in both bands with significant reduction in uncertainties. We are able for the first time to see the knee of the IRLF at z > 2 and observe a flattening of the faint-end slope as redshift increases. The bolometric luminosity density, a proxy for the cosmic black hole accretion history, computed from our LFs, shows a peak at z ≈ 2.25, consistent with recent estimates of the peak in the star formation rate density (SFRD). However, at earlier epochs, the AGN luminosity density is flatter than the SFRD. If confirmed, this result suggests that the build up of black hole mass outpaces the growth of stellar mass in high-mass systems at z ≳ 2.5. This is consistent with observations of redshift z ∼ 6 quasars that lie above the local M − σ relationship. The luminosity density derived from the IRLF is higher than that from the XLF at all redshifts. This is consistent with the dominant role of obscured AGN activity in the cosmic growth of supermassive black holes.
APA, Harvard, Vancouver, ISO, and other styles
4

Melini, Gabriele, Fabio La Franca, and Fabrizio Fiore. "Feedback from AGN: The Kinetic/Radio Luminosity Function." Proceedings of the International Astronomical Union 5, S267 (August 2009): 402. http://dx.doi.org/10.1017/s1743921310006861.

Full text
Abstract:
We have measured the probability distribution function of the ratio RX = log L1.4/LX, where L1.4/LX = ν Lν(1.4 GHz)/LX(2–10 keV), between the 1.4 GHz and the unabsorbed 2–10 keV luminosities and its dependence on LX and z. We have used a complete sample of ~1800 hard X-ray selected AGN, observed in the 1.4 GHz band, cross-correlated in order to exclude FR II-type objects, and thus obtain a contemporaneous measure of the radio and X-ray emission. The distribution P(RX|LX,z) is shown in Figure 1. Convolution of the distribution P(RX|LX,z) with the 2–10 keV X-ray AGN luminosity function from La Franca et al. (2005) and the relations between radio power and kinetic energy from Best et al. (2006) and Willott et al. (1999) allows us to derive the AGN kinetic power and its evolution. As shown in Figure 1, our results are in good agreement with the predictions of the most recent models of galaxy formation and evolution (e.g., Croton et al. 2006), where AGN radio feedback is required to quench the star formation.
APA, Harvard, Vancouver, ISO, and other styles
5

Meurs, E. J. A. "A nuclear Luminosity Function for Seyferts." Symposium - International Astronomical Union 175 (1996): 541–42. http://dx.doi.org/10.1017/s007418090008178x.

Full text
Abstract:
Relations between various classes of AGN should show up when examining their LFs. For Seyfert galaxies, such studies have been affected by the prevalence of (essentially) integrated magnitudes. Proper nuclear magnitudes have been determined in an effort of CCD imaging, which enable an appropriate comparison with QSOs.
APA, Harvard, Vancouver, ISO, and other styles
6

Liu, Chenxu, Karl Gebhardt, Erin Mentuch Cooper, Yechi Zhang, Donald P. Schneider, Robin Ciardullo, Dustin Davis, et al. "The Active Galactic Nuclei in the Hobby–Eberly Telescope Dark Energy Experiment Survey (HETDEX). II. Luminosity Function." Astrophysical Journal 935, no. 2 (August 1, 2022): 132. http://dx.doi.org/10.3847/1538-4357/ac8054.

Full text
Abstract:
Abstract We present the Lyα emission line luminosity function (LF) of the active galactic nuclei (AGN) in the first release of the Hobby–Eberly Telescope Dark Energy Experiment Survey (HETDEX) AGN catalog. The AGN are selected either by emission line pairs characteristic of AGN or by a single broad emission line, free of any photometric preselections (magnitude/color/morphology). The sample consists of 2346 AGN spanning 1.88 < z < 3.53, covering an effective area of 30.61 deg2. Approximately 2.6% of the HETDEX AGN are not detected at >5σ confidence at r ∼ 26 in the deepest r-band images we have searched. The Lyα line luminosity ranges from ∼1042.3 to 1045.9 erg s−1. Our Lyα LF shows a turnover luminosity with opposite slopes on the bright end and the faint end: The space density is highest at L Ly α ∗ = 10 43.4 erg s−1. We explore the evolution of the AGN LF over a broader redshift range (0.8 < z < 3); constructing the rest-frame ultraviolet (UV) LF with the 1450 Å monochromatic luminosity of the power-law component of the continuum (M1450) from M 1450 ∼ −18 to −27.5. We divide the sample into three redshift bins (z ∼ 1.5, 2.1, and 2.6). In all three redshift bins, our UV LFs indicate that the space density of AGN is highest at the turnover luminosity M 1450 * with opposite slopes on the bright end and the faint end. The M 1450 LFs in the three redshift bins can be well fit with a luminosity evolution and density evolution model: the turnover luminosity ( M 1450 * ) increases, and the turnover density (Φ*) decreases with increasing redshift.
APA, Harvard, Vancouver, ISO, and other styles
7

Fotopoulou, S., J. Buchner, I. Georgantopoulos, G. Hasinger, M. Salvato, A. Georgakakis, N. Cappelluti, et al. "The 5–10 keV AGN luminosity function at 0.01." Astronomy & Astrophysics 587 (March 2016): A142. http://dx.doi.org/10.1051/0004-6361/201424763.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Miyaji, T., G. Hasinger, and M. Schmidt. "Soft X-ray AGN luminosity function from ROSAT surveys." Astronomy and Astrophysics 369, no. 1 (April 2001): 49–56. http://dx.doi.org/10.1051/0004-6361:20010102.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Hasinger, G. "The X-Ray Background and the AGN Luminosity Function." Symposium - International Astronomical Union 183 (1999): 200–209. http://dx.doi.org/10.1017/s007418090013253x.

Full text
Abstract:
ROSAT deep and shallow surveys have provided an almost complete inventory of the constituents of the soft X-ray background which led to a population synthesis model for the whole X-ray background with interesting cosmological consequences. According to this model the X-ray background is the “echo” of mass accretion onto supermassive black holes, integrated over cosmic time. A new determination of the soft X-ray luminosity function of active galactic nuclei (AGN) is consistent with pure density evolution, and the comoving volume density of AGN at redshift 2–3 approaches that of local normal galaxies. This indicates that many larger galaxies contain black holes and it is likely that the bulk of the black holes was produced before most of the stars in the universe. However, only X-ray surveys in the harder energy bands, where the maximum of the energy density of the X-ray background resides, will provide the acid test of this picture.
APA, Harvard, Vancouver, ISO, and other styles
10

Ceraj, L., V. Smolčić, I. Delvecchio, M. Novak, G. Zamorani, J. Delhaize, E. Schinnerer, E. Vardoulaki, and N. Herrera Ruiz. "The VLA-COSMOS 3 GHz Large Project: Star formation properties and radio luminosity functions of AGN with moderate-to-high radiative luminosities out to z∼ 6." Astronomy & Astrophysics 620 (December 2018): A192. http://dx.doi.org/10.1051/0004-6361/201833935.

Full text
Abstract:
We have studied a sample of 1604 moderate-to-high radiative luminosity active galactic nuclei (HLAGN) selected at 3 GHz within the VLA-COSMOS 3 GHz Large Project. These were classified by combining multiple AGN diagnostics: X-ray data, mid-infrared data and broadband spectral energy distribution fitting. We decomposed the total radio 1.4 GHz luminosity (L1.4 GHz, TOT) into the emission originating from star formation and AGN activity by measuring the excess in L1.4 GHz, TOT relative to the infrared-radio correlation of star-forming galaxies. To quantify the excess, for each source we calculated the AGN fraction (fAGN) defined as the fractional contribution of AGN activity to L1.4 GHz, TOT. The majority of the HLAGN, (68.0 ± 1.5)%, are dominated by star-forming processes (fAGN ≤ 0.5), while (32.0 ± 1.5)% are dominated by AGN-related radio emission (0.5 < fAGN ≤ 1). We used the AGN-related 1.4 GHz emission to derive the 1.4 GHz AGN luminosity functions of HLAGN. By assuming pure density and pure luminosity evolution models we constrained their cosmic evolution out to z ∼ 6, finding Φ*(z)∝(1 + z)(2.64 ± 0.10)+(−0.61 ± 0.04)z and L*(z)∝(1 + z)(3.97 ± 0.15)+(−0.92 ± 0.06)z. These evolutionary laws show that the number and luminosity density of HLAGN increased from higher redshifts (z ∼ 6) up to a maximum in the redshift range 1 < z < 2.5, followed by a decline toward local values. By scaling the 1.4 GHz AGN luminosity to kinetic luminosity using the standard conversion, we estimate the kinetic luminosity density as a function of redshift. We compare our result to the semi-analytic models of radio mode feedback, and find that this feedback could have played an important role in the context of AGN-host co-evolution in HLAGN which shows evidence of AGN-related radio emission (fAGN > 0).
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "AGN luminosity function"

1

Aird, James. "Evolution of the X-ray Luminosity Function of AGN." Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501188.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Kuhlbrodt, Björn. "Analysis of Quasar images the luminosity function of AGN host galaxies /." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=968467814.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Barai, Paramita. "Modeling the Power Evolution of Classical Double Radio Galaxies over Cosmological Scales." Digital Archive @ GSU, 2006. http://digitalarchive.gsu.edu/phy_astr_diss/9.

Full text
Abstract:
During the quasar era (redshifts between 1 and 3) Radio Galaxies (RGs) have been claimed to have substantially influenced the growth and evolution of large scale structures in the universe. In this dissertation I test the robustness of these exciting claims. In order to probe the impacts in more detail, good theoretical models for such RG systems are required. With this motivation, I seek to develop an essentially analytical model for the evolution of Fanaroff-Riley Class II radio galaxies both as they age individually and as their numbers vary with cosmological epoch. To do so, I first compare three sophisticated semi-analytical models for the dynamical and radio lobe power evolution of FR II galaxies, those given by Kaiser, Dennett-Thorpe & Alexander (1997, KDA), Blundell, Rawlings, & Willott (1999, BRW) and Manolakou & Kirk (2002, MK). I perform multi-dimensional Monte Carlo simulations leading to virtual radio surveys. The predictions of each model for redshift, radio power (at 151 MHz), linear size and spectral index are then compared with data. The observational samples are the low frequency radio surveys, 3CRR, 6CE and 7CRS, which are flux-limited and redshift complete. I next perform extensive statistical tests to compare the distributions of model radio source parameters and those of the observational samples. The statistics used are the 1-Dimensional and 2-Dimensional Kolmogorov-Smirnov (K-S) tests and the 4-variable Spearman partial rank correlation coefficient. I search for and describe the "best" parameters for each model. I then produced modifications to each of the three original models, and extensively compare the original and the modified model performances in fitting the data. The key result of my dissertation is that using the Radio Luminosity Function of Willott et al. (2001) as the redshift birth function of radio sources, the KDA and MK models perform better than the BRW models in fitting the 3CRR, 6CE and 7CRS survey data when using K-S based statistical tests, and the KDA model provides the best fits to the correlation coefficients. However, no pre-existing or modified model can provide adequate fits for the spectral indices. I also calculate the volume fraction of the relevant universe filled by the generations of radio galaxies over the quasar era. This volume filling factor is not as large as estimated earlier. Nonetheless, the allowed ranges of various model parameters produce a rather wide range of astrophysically interesting relevant volume fraction values. I conclude that the expanding RGs born during the quasar era may still play significant roles in the cosmological history of the universe.
APA, Harvard, Vancouver, ISO, and other styles
4

Gavignaud, Isabelle. "Propriétés statistiques des AGN de faibles luminositées." Phd thesis, Université Paul Sabatier - Toulouse III, 2006. http://tel.archives-ouvertes.fr/tel-00123824.

Full text
Abstract:
Ces dernières années les principaux relevés cosmologiques ont collectés plusieurs dizaines de milliers de spectres de noyaux actifs de galaxies (connus aussi sous l'abréviation anglaise AGN), illustrant ainsi la grande éfficacité des techniques de pré-sélections optiques de candidat AGN. Ils ont ainsi permis une étude statistique détaillée de la population d'AGN.
Le revers de ces techniques de pré-sélection est que certaines catégories de la population globale des AGN optiques sont peut-être sous-représentées dans ces échantillons, biaisant notre compréhension actuelle de l'évolution de ces objets.

Cette thèse de doctorat est dédiée à l'étude des propriétés des AGN de type 1 de faible luminosité. Dans ce but nous utilisons un échantillon spectroscopique de 130 AGN à raies
d'émission larges, extrait d'un grand relevé de galaxie: le VIRMOS VLT Deep Survey (VVDS).
Cet échantillon présente un intérêt unique, de part la simplicité des critères de pré-sélection de ces objets (une simple limite en magnitude) ainsi que par la profondeur en magnitude atteinte: il fournit d'une part un aperçu des propriétés des AGN de type 1 à des magnitudes encore peu explorées spectroscopiquement (les AGN étudiés ici sont jusqu'à cent fois plus faibles que ceux du SDSS) et il permet d'autre part de quantifier les biais qui seraient introduits par des critères classiques de sélection.

Nous mesurons une densité sur le ciel d'environ 470 AGN par degré carré à notre magnitude limite (Iab=24). Une fraction importante des AGN que nous observons ne serait pas sélectionée par les techniques de sélections morphologiques et d'excès d'UV classiquement appliquées. Nous attribuons cet effet à la contamination de nos AGN par leur galaxie hôte, vue leur faible luminosité. La fonction de luminosité des AGN montre qu'il y a relativement plus d'AGN de faible luminosité à bas redshift qu'á plus grand redshift. Cette observation corrobore le scénario de croissance anti-hierarchique de trous-noirs galactiques suggéré par les echantillons d'AGN sélectionnés en rayons-X.
Finalement nous nous sommes intéressés à la nature des trous noirs qui sont à l'origine de nos AGN. S'agit-il de petits trous noirs galactiques ou bien, au contraire, de trous noirs de grandes masses accrétant faiblement ?
Nos résultats, encore préliminaires, suggèrent que nos AGN correspondent en moyenne à des trous noirs galactique de masses intermediaires (~100 millions de masses solaires) accrétant à des taux d'Eddington modeste (~< 10%).
APA, Harvard, Vancouver, ISO, and other styles
5

Brogan, Róisín O'Rourke. "Testing the multi-epoch luminosity function of asymptotic giant branch stars in the Small Magellanic Cloud with VISTA." Thesis, Uppsala universitet, Institutionen för fysik och astronomi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-419074.

Full text
Abstract:
The physics pertaining to the asymptotic giant branch (AGB) phase of stellar evolution has been studied for many years. However, the mechanics behind many characteristics displayed at this stage are still not fully understood. As a member of the Long Period Variable class of stars, AGB stars are invaluable in creating three-dimensional maps of the Milky Way, the Magellanic System and other galaxies with resolved stellar populations. Variable stars can be used to determine radial distances from Earth using their periodic luminosity variations. As this type of star has unknown qualities, models of AGB populations need to be calibrated with observed data. Previous research has derived a best-fitting model using the TRILEGAL code (a TRIdimensional modeL of thE GALaxy). This model was calibrated against single-epoch luminosity functions (LFs) calculated from resolved stellar populations in the Small Magellanic Cloud (SMC). With multi-epoch data now available from the VISTA survey of the Magellanic Clouds (VMC), this best-fitting model can now be compared with the LFs as they vary with time. Firstly, statistical tests are completed to measure the extent of the LF variation between epochs and from the mean LF for both the full VMC AGB catalogue and for the oxygen-rich, carbon-rich and extreme AGB classes. Statistical tests are then performed to measure the similarity between the LFs from different epochs and the simulated LFs, again for the entire sample and the three classes. This investigation shows that, while the current best-fitting model is a good approximation of many individual epochs’ AGB LFs in the SMC to within 3σ, inclusion of multi-epoch data would make for a more robust analysis. In order to do this, it would be desirable to have more epochs with deeper and regular observations that could cover full lightcurves of some of the sources. There also seems to be a statistical difference between the inner and outer areas of the SMC, perhaps due to tidal disruptions. It would be interesting to see the results of a similar study using the LMC, which is less affected by the gravitational influence of its smaller companion.

This thesis was written under the supervision of Maria-Rosa Cioni at the Leibniz Institute for Astrophysics in Potsdam. The presentation was held online due to the COVID-19 pandemic.

APA, Harvard, Vancouver, ISO, and other styles
6

Kuhlbrodt, Björn [Verfasser]. "Analysis of Quasar images : the luminosity function of AGN host galaxies / vorgelegt von Björn Kuhlbrodt." 2003. http://d-nb.info/968467814/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Patten, Brian Michael. "The evolution of rotation and activity in young open clusters : the zero-age main sequence." Thesis, 1995. http://hdl.handle.net/10125/9356.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Trottier, Charles. "Vers la détermination de la composition du coeur des étoiles naines blanches." Thèse, 2009. http://hdl.handle.net/1866/8021.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "AGN luminosity function"

1

Baker, A. C., and P. C. Hewett. "K-Correction Biases and the Quasar Luminosity Function." In Multi-Wavelength Continuum Emission of AGN, 498. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-010-9537-2_196.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Padovani, Paolo, and C. Megan Urry. "Luminosity Functions, Relativistic Beaming, and Unified Theories of AGN." In Physics of Active Galactic Nuclei, 642–48. Berlin, Heidelberg: Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-642-77566-6_145.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Wood, M. A. "The Age and Formation of the Galaxy: Clues from the White Dwarf Luminosity Function." In White Dwarfs, 89–97. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3230-5_9.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Smith, J. Allyn, Terry D. Oswalt, and Matt A. Wood. "A Lower Limit to the Age of The Galaxy from the White Dwarf Luminosity Function." In White Dwarfs, 399–400. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-010-0215-8_124.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Leggett, S. K., P. Bergeron, and Maria Teresa Ruiz. "New Model Atmosphere Analyses of Cool White Dwarfs: A Revised Luminosity Function and Constraints on the Age of the Galaxy." In Fundamental Stellar Properties: The Interaction Between Observation and Theory, 429–32. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-011-5602-8_56.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Favata, F., G. Micela, and S. Sciortino. "An Analysis of the Stellar Content of the Einstein Extended Medium Sensitivity Survey Using Age-Homogeneous X-Ray Luminosity Functions." In Physics of Solar and Stellar Coronae: G.S. Vaiana Memorial Symposium, 287–90. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1964-1_33.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

"The Quasar Luminosity Function and Evolution." In An Introduction to Active Galactic Nuclei, 175–93. Cambridge University Press, 1997. http://dx.doi.org/10.1017/cbo9781139170901.012.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "AGN luminosity function"

1

UEDA, Y., M. AKIYAMA, K. OHTA, and T. MIYAJI. "COSMOLOGICAL EVOLUTION OF THE HARD X-RAY AGN LUMINOSITY FUNCTION." In Proceedings of the Guillermo Haro Conference 2003. WORLD SCIENTIFIC, 2004. http://dx.doi.org/10.1142/9789812702432_0082.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Bagchi, Manjari, Duncan R. Lorimer, Marta Burgay, Nicolò D’Amico, Paolo Esposito, Alberto Pellizzoni, and Andrea Possenti. "The luminosity function of cluster pulsars." In RADIO PULSARS: AN ASTROPHYSICAL KEY TO UNLOCK THE SECRETS OF THE UNIVERSE. AIP, 2011. http://dx.doi.org/10.1063/1.3615109.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Souza, Marco Aurelio Bastos, Edson Eduardo Borges da Silva, João Pedro Mantovani Tarrega, Renato Tinós, and Ariadne de Andrade Costa. "Simulation of Rat Behavior in a Light-Dark Box via Neuroevolution." In Encontro Nacional de Inteligência Artificial e Computacional. Sociedade Brasileira de Computação - SBC, 2022. http://dx.doi.org/10.5753/eniac.2022.227630.

Full text
Abstract:
The light-dark box is a widely used test for the investigation of animal behavior commonly used to identify and study anxious-like behavioral patterns in rodents. We propose a neuroevolution model for virtual rats in a simulated light-dark box. The virtual rat is controlled by an artificial neural network (ANN) optimized by a genetic algorithm (GA). The fitness function is given by a weighed sum of two terms (punishment and reward). By changing the weight of the punishment term, we are able to simulate the effects of anxiolytic/anxiogenic drugs on rats. We also propose using GAs to optimize the number of the ANN hidden neurons and sensors for the virtual rat. According to the experiments, the best results are obtained by ANNs combining both luminosity and wall sensors.
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "AGN luminosity function"

1

Zilberman, Mark. "Doppler De-boosting" and the Observation of "Standard Candles" in Cosmology. Intellectual Archive, July 2021. http://dx.doi.org/10.32370/iaj.2552.

Full text
Abstract:
“Doppler boosting” is a well-known relativistic effect that alters the apparent luminosity of approaching radiation sources. “Doppler de-boosting” is the same relativistic effect observed but for receding light sources (e.g. relativistic jets of AGN and GRB). “Doppler boosting” alters the apparent luminosity of approaching light sources to appear brighter, while “Doppler de-boosting” alters the apparent luminosity of receding light sources to appear fainter. While “Doppler de-boosting” has been successfully accounted for and observed in relativistic jets of AGN, it was ignored in the establishment of Standard candles for cosmological distances. A Standard Candle adjustment of Z>0.1 is necessary for “Doppler de-boosting”, otherwise we would incorrectly assume that Standard Candles appear dimmer, not because of “Doppler de-boosting” but because of the excessive distance, which would affect the entire Standard Candles ladder at cosmological distances. The ratio between apparent (L) and intrinsic (Lo) luminosities as a function of the redshift Z and spectral index α is given by the formula ℳ(Z) = L/Lo=(Z+1)α -3 and for Type Ia supernova appears as ℳ(Z) = L/Lo=(Z+1)-2. “Doppler de-boosting” may also explain the anomalously low luminosity of objects with a high Z without the introduction of an accelerated expansion of the Universe and Dark Energy.
APA, Harvard, Vancouver, ISO, and other styles
2

Zilberman, Mark. Shouldn’t Doppler 'De-boosting' be accounted for in calculations of intrinsic luminosity of Standard Candles? Intellectual Archive, September 2021. http://dx.doi.org/10.32370/iaj.2569.

Full text
Abstract:
"Doppler boosting / de-boosting" is a well-known relativistic effect that alters the apparent luminosity of approaching/receding radiation sources. "Doppler boosting" alters the apparent luminosity of approaching light sources to appear brighter, while "Doppler de-boosting" alters the apparent luminosity of receding light sources to appear fainter. While "Doppler boosting / de-boosting" has been successfully accounted for and observed in relativistic jets of AGN, double white dwarfs, in search of exoplanets and stars in binary systems it was ignored in the establishment of Standard Candles for cosmological distances. A Standard Candle adjustment appears necessary for "Doppler de-boosting" for high Z, otherwise we would incorrectly assume that Standard Candles appear dimmer, not because of "Doppler de-boosting" but because of the excessive distance, which would affect the entire Standard Candles ladder at cosmological distances. The ratio between apparent (L) and intrinsic (Lo) luminosities as a function of redshift Z and spectral index α is given by the formula ℳ(Z) = L/Lo=(Z+1)^(α-3) and for Type Ia supernova as ℳ(Z) = L/Lo=(Z+1)^(-2). These formulas are obtained within the framework of Special Relativity and may require adjustments within the General Relativity framework.
APA, Harvard, Vancouver, ISO, and other styles
3

Zilberman, Mark. “Doppler de-boosting” and the observation of “Standard candles” in cosmology. Intellectual Archive, July 2021. http://dx.doi.org/10.32370/iaj.2549.

Full text
Abstract:
“Doppler boosting” is a well-known relativistic effect that alters the apparent luminosity of approaching radiation sources. “Doppler de-boosting” is the name of relativistic effect observed for receding light sources (e.g. relativistic jets of active galactic nuclei and gamma-ray bursts). “Doppler boosting” changes the apparent luminosity of approaching light sources to appear brighter, while “Doppler de-boosting” causes the apparent luminosity of receding light sources to appear fainter. While “Doppler de-boosting” has been successfully accounted for and observed in relativistic jets of AGN, it was ignored in the establishment of Standard candles for cosmological distances. A Standard candle adjustment of an Z>0.1 is necessary for “Doppler de-boosting”, otherwise we would incorrectly assume that Standard Candles appear dimmer not because of “Doppler de-boosting” but because of the excessive distance, which would affect the entire Standard Candles ladder at cosmological distances. The ratio between apparent (L) and intrinsic (Lo) luminosities as a function of the redshift Z and spectral index α is given by the formula ℳ(Z) = L/Lo=(Z+1)α -3 and for Type Ia supernova appears as ℳ(Z) = L/Lo=(Z+1)-2. “Doppler de-boosting” may also explain the anomalously low luminosity of objects with a high Z without the introduction of an accelerated expansion of the Universe and Dark Energy.
APA, Harvard, Vancouver, ISO, and other styles
4

Zilberman, Mark. PREPRINT. “Doppler de-boosting” and the observation of “Standard candles” in cosmology. Intellectual Archive, June 2021. http://dx.doi.org/10.32370/ia_2021_06_23.

Full text
Abstract:
PREPRINT. “Doppler boosting” is a well-known relativistic effect that alters the apparent luminosity of approaching radiation sources. “Doppler de-boosting” is the term of the same relativistic effect observed for receding light sources (e.g.relativistic jets of active galactic nuclei and gamma-ray bursts). “Doppler boosting” alters the apparent luminosity of approaching light sources to appear brighter, while “Doppler de-boosting” alters the apparent luminosity of receding light sources to appear fainter. While “Doppler de-boosting” has been successfully accounted for and observed in relativistic jets of AGN, it was ignored in the establishment of Standard candles for cosmological distances. A Standard candle adjustment of Z>0.1 is necessary for “Doppler de-boosting”, otherwise we would incorrectly assume that Standard Candles appear dimmer, not because of “Doppler de-boosting” but because of the excessive distance, which would affect the entire Standard Candles ladder at cosmological distances. The ratio between apparent (L) and intrinsic (Lo) luminosities as a function of the redshift Z and spectral index α is given by the formula ℳ(Z) =L/Lo=(Z+1)^(α-3) and for Type Ia supernova appears as ℳ(Z)=L/Lo=(Z+1)^(-2). “Doppler de-boosting” may also explain the anomalously low luminosity of objects with a high Z without the introduction of an accelerated expansion of the Universe and Dark Energy.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'AGN luminosity function' for particular source types:
Journal articles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography