Results 21 to 30 of about 254 (135)

Systematizing Decisions in Design‐Based Research: From Theory to Design

Science Education, Volume 109, Issue 2, Page 523-536, March 2025.
ABSTRACT There is a general consensus that design‐based research (DBR) is a genre of approaches in education research to design interventions for specific problems with the aim to gain an understanding of how they work in the problem context. While there is a considerable body of literature discussing the epistemic and methodological aspects of DBR, we
Markus Obczovsky, Angelika Bernsteiner, Claudia Haagen‐Schützenhöfer, Thomas Schubatzky   +3 more
wiley   +1 more source

Correlation and time delays of the X-ray and optical emission of the Seyfert Galaxy NGC 3783 [PDF]

, 2009
We present simultaneous X-ray and optical B- and V-band light curves of the Seyfert Galaxy NGC 3783 spanning 2 years. The flux in all bands is highly variable and the fluctuations are significantly correlated. As shown before by Stirpe et al. the optical
Lira Teillery, Paulina María, Lira, P., Lira, Paulina, Churazov, E., Arévalo, P., Breedt, Elme, Breedt, E., Lira Teillery, Paulina, McHardy, Ian M., McHardy, I. M., Uttley, Philip, Uttley, P., McHardy, I.   +12 more
core   +1 more source

The Remarkably Featureless High-Resolution X-Ray Spectrum of Markarian 478 [PDF]

, 2003
An observation of Mrk 478 using the Chandra Low Energy Transmission Grating Spectrometer is presented. The source exhibited 30-40% flux variations on timescales of order 10000 s together with a slow decline in the spectral softness over the full 80 ks ...
Warwick, Robert, Edelson, Rick A, Vaughan, Simon, O'Brien, Paul, Marshall, Herman L, Malkan, Matthew   +5 more
core   +1 more source

Intensive disc-reverberation mapping of Fairall 9 : 1st year of Swift & LCO monitoring [PDF]

, 2020
Funding: UK STFC grant ST/R000824/1 (KH).We present results of time-series analysis of the first year of the Fairall 9 intensive disc-reverberation campaign.
Joner, M.D., Korista, K, Evans, P.A., Onken, C. A., Page, KL, Bisogni, S., Barth, A.J., Mudd, D., Siegel, M., Brandt, W.N., K Horne (7709303), Breeveld, A.A., G Kriss (7739231), F Marshall (7789220), Cackett, E, Lohfink, A. M., Valenti, S, Schmidt, T, Horne, K, Dalla Bontà, E, Horne, K., Gonzalez-Buitrago, D. H., Bisogni, Susanna, D Mudd (7739234), Bontà, E. Dalla, Cenko, SB, Gelbord, J.M., M Siegel (7719356), AJ Barth (7709273), Santisteban, J V Hernández, Cackett, E. M., Cenko, S B, Joner, MD, Mathur, S, S Bisogni (7709279), Schmidt, T., Santisteban, J. V. Hernández, Santisteban, JVH, Goad, M. R., SB Cenko (7637768), Onken, C.A., Uttley, P, CA Onken (9209699), DH Gonzalez-Buitrago (9249098), High Energy Astrophys. & Astropart. Phys (API, FNWI), R Edelson (7739195), Dalla Bonta, E., Vaughan, S., Gelbord, J M, Kriss, G, M Mehdipour (7709255), Joner, M. D., Grupe, D, WN Brandt (7709282), Marshall, F., Siegel, M, Page, K L, LaPorte, SJ, P Uttley (7739216), Mathur, S., D Grupe (7613144), SJ LaPorte (9249101), Joner, M D, Evans, P A, LaPorte, S. J., Cackett, E.M., Bontà, ED, Peterson, B.M., Mehdipour, M, Vestergaard, M, Brandt, WN, Lohfink, A.M., Hernández Santisteban, J.V., Bisogni, S, Page, K.L., Vestergaard, M., Mehdipour, M., Starkey, D, Hernandez Santisteban, J. V., G Ferland (7739222), Cenko, S.B., Goad, M, Gonzalez-Buitrago, DH, MR Goad (7613117), Ferland, G, M Vestergaard (7709324), Marshall, F, Breeveld, AA, Barth, A., Valenti, S., KL Page (7612922), Uttley, P., Breeveld, A. A., H Netzer (7739213), Cackett, EM, Barth, A J, LaPorte, S.J., Ferland, G., E Dalla Bontà (9249095), Mudd, D, Grupe, D., Peterson, BM, Vaughan, S, Cackett, E M, K Korista (7739210), MD Joner (7804577), Goad, MR, S Valenti (7651277), PA Evans (7668497), BM Peterson (7709249), Breeveld, A A, Lohfink, A M, Netzer, H., Brandt, W N, Gelbord, J. M., Uttley, Phil, Peterson, B. M., Edelson, R, Kriss, G., Brandt, W. N., Gonzalez-Buitrago, D H, EM Cackett (7785308), LaPorte, S J, Korista, K., AM Lohfink (9249092), Evans, PA, Gelbord, JM, AA Breeveld (7613711), Onken, CA, SCHMIDT, TOBIAS MARIUS, Page, K. L., Peterson, B M, Gonzalez-Buitrago, D.H., JV Hernández Santisteban (9249089), Lohfink, AM, JM Gelbord (7709297), S Vaughan (7646927), Evans, P. A., Santisteban, J. V.Hernández, Barth, A. J., D Starkey (7768826), Onken, C A, Gelbord, J., Brandt, W. N, Edelson, R., Cenko, S. B., Starkey, D., Barth, AJ, S Mathur (7709252), Goad, M R, Goad, M.R., Netzer, H, T Schmidt (7721066)   +152 more
core   +1 more source

Highly ionized Fe K alpha emission lines from the LINER galaxy M 81 [PDF]

, 2004
We present spectral and timing results from a long (130 ks) XMM-Newton EPIC observation of the nucleus of the Seyfert/LINER galaxy M 81. During the observation the X-ray flux varied by 20%, but there was no significant change in spectral shape.
Page, MJ, Soria, R, Page, M.J., Wu, K, Starling, R.L.C., K. Wu, Soria, R., Wu, K., Starling, RLC, M. J. Page, R. L. C. Starling, Zane, S, S. Zane, Zane, S., R. Soria   +14 more
core   +1 more source

The nature and origin of Seyfert warm absorbers

, 2005
We collate the results of recent high resolution X-ray spectroscopic observations of 23 AGN, and use the resulting information to try to provide answers to some of the main open questions about warm absorbers: where do they originate, what effect do they
Page, MJ, M. J. Page, A. J. Blustin, Fuerst, SV, Branduardi-Raymont, G, C. E. Ashton, G. Branduardi-Raymont, S. V. Fuerst, Ashton, CE, Blustin, AJ   +9 more
core   +1 more source

The sloan digital sky survey reverberation mapping project : ensemble spectroscopic variability of quasar broad emission lines

, 2015
M.Y.S. acknowledges support from the China Scholarship Council (No. [2013]3009). J.R.T. and Y.S. acknowledge support from NASA through Hubble Fellowship grants #51330 and #51314, respectively, awarded by the Space Telescope Science Institute, which is ...
Shen, Y., Oravetz, D., Brandt, W. N., Bizyaev, D., Richards, Gordon T., Kinemuchi, Karen, Oravetz, Daniel, Sun, M., Brandt, W.N., Jiang, Linhua, Schneider, D.P., Dawson, Kyle, Hall, Patrick B., Dawson, K., Richards, G.T., Horne, Keith, Pan, Kaike, Hall, P.B., Jiang, L., Simmons, A., Schneider, Donald P., Horne, Keith Douglas, Shen, Yue, Trump, Jonathan R., Ho, L.C., Simmons, Audrey, Ho, Luis C., Pan, K., Bizyaev, Dmitry, Denney, K.D., Denney, Kelly D., Trump, J.R., Sun, Mouyuan, Kinemuchi, K.   +33 more
core   +1 more source

AGN evolution, clustering and the X-ray background [PDF]

, 1991
We combine optical, X-ray (Einstein and ROSAT) and infrared (IRAS) data to investigate the evolution and spatial distribution of AGN with particular emphasis on the implications for the origin of the diffuse X-ray background.
Georgantopoulos, Ioannis
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XMM-Newton observation of the highly magnetised accreting pulsar Swift J045106.8-694803: evidence of a hot thermal excess

, 2013
Several persistent, low luminosity (LX ~ 1034 erg s-1), long spin period (P > 100 s) High Mass X-ray Binaries have been reported with blackbody components with temperatures > 1 keV.
Bartlett, Elizabeth, Ho, Wynn C.G., Coe, Malcolm J.   +2 more
core   +1 more source

Centrum: Working Papers of the Minnesota Center for Advanced Studies in Language, Style, and Literary Theory. Volume 3, Number 1, Spring 1975

, 1975
Publication of Centrum is made possible by grants from the Graduate School of the University of Minnesota and the McKnight Foundation.Articles: On the possibility of a general theory of literature / F.E. Sparshott. What is literary theory?

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