Browsing Institutt for teoretisk astrofysikk by Author "Dahle, Håkon"

Now showing items 1-20 of 50

  • A 30 kpc chain of "beads on a string" star formation between two merging early type galaxies in the core of a strong-lensing galaxy cluster 
    Tremblay, G. R.; Gladders, M. D.; Baum, S. A.; O'Dea, C. P.; Bayliss, M. B.; Cooke, K. C.; Dahle, Håkon; Davis, T. A.; Florian, M.; Rigby, J. R.; Sharon, K.; Soto, E; Wuyts, E (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    New Hubble Space Telescope ultraviolet and optical imaging of the strong-lensing galaxy cluster SDSS J1531+3414 (z = 0.335) reveals two centrally dominant elliptical galaxies participating in an ongoing major merger. The ...
  • Accurately predicting the escape fraction of ionizing photons using rest-frame ultraviolet absorption lines 
    Chisholm, John; Gazagnes, S; Schaerer, Daniel; Verhamme, Anne; Rigby, Jane R.; Bayliss, Matthew B.; Sharon, Keren; Gladders, Michael D.; Dahle, Håkon (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    The fraction of ionizing photons that escape high-redshift galaxies sensitively determines whether galaxies reionized the early Universe. However, this escape fraction cannot be measured from high-redshift galaxies because ...
  • Andromeda’s Parachute: Time Delays and Hubble Constant 
    Shalyapin, Vyacheslav N.; Goicoechea, Luis J.; Dyrland, Karianne; Dahle, Håkon (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    The gravitational lens system PS J0147+4630 (Andromeda’s Parachute) consists of four quasar images ABCD and a lensing galaxy. We obtained r -band light curves of ABCD in the 2017−2022 period from monitoring with two 2 m ...
  • “Beads-on-a-string” Star Formation Tied to One of the Most Powerful Active Galactic Nucleus Outbursts Observed in a Cool-core Galaxy Cluster 
    Omoruyi, Osase; Tremblay, Grant R.; Combes, Francoise; Davis, Timothy A.; Gladders, Michael D.; Vikhlinin, Alexey; Nulsen, Paul; Kharb, Preeti; Baum, Stefi A.; O’Dea, Christopher P.; Sharon, Keren; Terrazas, Bryan A.; Nevin, Rebecca; Schechter, Aimee L.; Zuhone, John A.; McDonald, Michael; Dahle, Håkon; Bayliss, Matthew B.; Connor, Thomas; Florian, Michael; Rigby, Jane R.; Vaddi, Sravani (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2024)
    With two central galaxies engaged in a major merger and a remarkable chain of 19 young stellar superclusters wound around them in projection, the galaxy cluster SDSS J1531+3414 (z = 0.335) offers an excellent laboratory ...
  • C III] Emission in Star-forming Galaxies Near and Far 
    Rigby, J. R.; Bayliss, M. B.; Gladders, M. D.; Sharon, K.; Wuyts, E; Dahle, Håkon; Johnson, T.; Peña-Guerrero, M. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    We measure [C iii] 1907, C iii] 1909 Å emission lines in 11 gravitationally lensed star-forming galaxies at z ~ 1.6–3, finding much lower equivalent widths than previously reported for fainter lensed galaxies. While it is ...
  • CHANDRA and XMM-NEWTON OBSERVATIONS OF THE MERGING CLUSTER OF GALAXIES PLCK G036.7+14.9 
    Zhang, B; David, L. P.; Jones, C.; Andrade-Santos, F.; O'Sullivan, E.; Dahle, Håkon; Nulsen, P. E. J.; Clarke, T. E.; Pointecouteau, E; Pratt, G. W.; Arnaud, M.; Vrtilek, J. M.; Ji, L.; van Weeren, R. J.; Kraft, R. P.; Kong, X. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    We present Chandra and XMM-Newton observations of PLCK G036.7+14.9 from the Chandra–Planck Legacy Program. The high resolution X-ray observations reveal two close (~72'' = 193 kpc in projection) subclusters, G036N and ...
  • Chandra measurements of a complete sample of X-ray luminous galaxy clusters: The luminosity-mass relation 
    Giles, P. A.; Maughan, B. J.; Dahle, Håkon; Bonamente, M.; Landry, D.; Jones, C.; Joy, M.; Murray, S. S.; van der Pyl, N. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    We present the results of work involving a statistically complete sample of 34 galaxy clusters, in the redshift range 0.15 ≤ z ≤ 0.3 observed with Chandra. We investigate the luminosity–mass (LM) relation for the cluster ...
  • Comparison of Sunyaev-Zel'dovich measurements from Planck and from the Arcminute Microkelvin Imager for 99 galaxy clusters 
    Perrott, Y. C.; Olamaie, M.; Rumsey, C; Brown, M. L.; Feroz, F.; Grainge, K. J. B.; Hobson, M. P.; Lasenby, A. N.; MacTavish, C. J.; Pooley, G. G.; Saunders, R. D. E.; Schammel, M. P.; Scott, P. F.; Shimwell, T. W.; Titterington, D. J.; Waldram, E. M.; Aghanim, N.; Arnaud, M.; Ashdown, M.; Aussel, H; Barrena, R.; Bikmaev, I; Böhringer, H.; Burenin, R; Carvalho, P.; Chon, G.; Comis, B; Dahle, Håkon; Démoclès, J.; Douspis, M.; Harrison, D.; Hempel, A; Hurier, G.; Khamitov, I; Kneissl, R.; Macías-Pérez, J. F.; Melin, J.-B.; Pointecouteau, E.; Pratt, G. W.; Rubiño-Martín, J. A.; Stolyarov, V.; Sutton, D (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    We present observations and analysis of a sample of 123 galaxy clusters from the 2013 Planck catalogue of Sunyaev-Zel’dovich sources with the Arcminute Microkelvin Imager (AMI), a ground-based radio interferometer. AMI ...
  • Constraining the Metallicities, Ages, Star Formation Histories, and Ionizing Continua of Extragalactic Massive Star Populations 
    Chisholm, J.; Rigby, J. R.; Bayliss, M.; Berg, D. A.; Dahle, Håkon; Gladders, M.; Sharon, K. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    We infer the properties of massive star populations using the far-ultraviolet stellar continua of 61 star-forming galaxies: 42 at low redshift observed with the Hubble Space Telescope and 19 at z ~ 2 from the MegaSaura ...
  • COOL-LAMPS. Discovery of COOL J0335-1927, a Gravitationally Lensed Quasar at z=3.27 with an Image Separation of 23".3 
    Napier, Kate; Gladders, Michael D.; Sharon, Keren; Dahle, Håkon; Cloonan, Aidan P.; Mahler, Guillaume; Escapa, Isaiah; Garza, Josh; Kisare, Andrew; Malagon, Natalie; Mork, Simon; Niu, Kunwanhui; Rosener, Riley; Sullivan jr., Jamar; Tagliavia, Marie; Tamargo-Arizmendi, Marcos; Teixeira, Raul; Tsiane, Kabelo; Wagner, Grace; Zhang, Yunchong; Zhao, Megan (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
  • COOL-LAMPS. II. Characterizing the Size and Star Formation History of a Bright Strongly Lensed Early-type Galaxy at Redshift 1.02 
    Sukay, Ezra; Khullar, Gourav; Gladders, Michael D.; Sharon, Keren; Mahler, Guillaume; Napier, Kate; Bleem, Lindsey E.; Dahle, Håkon; Florian, Michael K.; Gozman, Katya; Lin, Jason J.; Martinez, Michael N.; Matthews Acuña, Owen S.; Medina, Elisabeth; Merz, Kaiya; Sanchez, Jorge A.; Sisco, Emily E.; Stein, Daniel J. Kavin; Tavangar, Kiyan; Whitaker, Katherine E. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    We present COOL J1323+0343, an early-type galaxy at z = 1.0153 ± 0.0006, strongly lensed by a cluster of galaxies at z = 0.353 ± 0.001. This object was originally imaged by DECaLS and noted as a gravitational lens by ...
  • COOL-LAMPS. III. Discovery of a 25″.9 Separation Quasar Lensed by a Merging Galaxy Cluster 
    Martinez, Michael N.; Napier, Kate A.; Cloonan, Aidan P.; Sukay, Ezra; Gozman, Katya; Merz, Kaiya; Khullar, Gourav; Lin, Jason J.; Matthews Acuña, Owen S.; Medina, Elisabeth; Sanchez, Jorge A.; Sisco, Emily E.; Kavin Stein, Daniel J.; Tavangar, Kiyan; González, Juan Remolina; Mahler, Guillaume; Sharon, Keren; Dahle, Håkon; Gladders, Michael D. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
  • COOL-LAMPS. IV. A Sample of Bright Strongly Lensed Galaxies at 3 < z < 4 
    Zhang, Yunchong; Manwadkar, Viraj; Gladders, Michael D.; Khullar, Gourav; Dahle, Håkon; Napier, Kate A.; Mahler, Guillaume; Sharon, Keren; Matthews Acuña, Owen S.; Ashmead, Finian; Cerny, William; Gonzàlez, Juan Remolina; Gozman, Katya; Levine, Benjamin C.; Marohnic, Daniel; Martinez, Michael N.; Merz, Kaiya; Pan, Yue; Sanchez, Jorge A.; Sierra, Isaac; Sisco, Emily E.; Sukay, Ezra; Tavangar, Kiyan; Zaborowski, Erik (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
  • COOL-LAMPS. VI. Lens Model and New Constraints on the Properties of COOL J1241+2219, a Bright z = 5 Lyman Break Galaxy and its z = 1 Cluster Lens 
    Klein, Maxwell; Sharon, Keren; Napier, Kate; Gladders, Michael D.; Khullar, Gourav; Bayliss, Matthew; Dahle, Håkon; Owens, M. Riley; Stark, Antony; Brownsberger, Sasha; Kim, Keunho J.; Kuchta, Nicole; Mahler, Guillaume; Smith, Grace; Walker, Ryan; Gozman, Katya; Martinez, Michael N.; Matthews Acuña, Owen S.; Merz, Kaiya; Sanchez, Jorge A.; Stein, Daniel J. Kavin; Sukay, Ezra O.; Tavangar, Kiyan (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2024)
  • Discovery of an exceptionally bright giant arc at z = 2.369, gravitationally lensed by the Planck cluster PSZ1 G311.65 - 18.48 
    Dahle, Håkon; Aghanim, Nabila; Guennou, L.; Hudelot, P.; Kneissl, R.; Pointecouteau, E.; Beelen, Anita; Bayliss, M; Douspis, M.; Nesvadba, N.; Hempel, A.; Gronke, Max Balthasar; Burenin, R.; Dole, H.; Harrison, Debbie; Mazzotta, P.; Sunyaev, R (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2016)
    As part of an all-sky follow-up of the Planck catalogue of Sunyaev-Zeldovich (SZ) cluster candidates detected in the first 14 months of data, we are observing cluster candidates in the southern sky in the optical imaging ...
  • Diversity in extinction laws of Type Ia supernovae measured between 0.2 and 2 μm 
    Amanullah, R.; Johansson, J.; Goobar, A.; Ferretti, R.; Papodogiannakis, S.; Petrushevska, T.; Brown, P. J.; Cao, Y.; Contreras, C.; Dahle, Håkon; Elias-Rosa, N.; Fynbo, J. P. U.; Gorosabel, J.; Guaita, L.; Hangard, L.; Howell, D. A.; Hsiao, E. Y.; Kankare, E.; Kasliwal, M.; Leloudas, G.; Lundqvist, P.; Mattila, S.; Nugent, P.; Phillips, M. M.; Sandberg, A.; Stanishev, V.; Sullivan, M.; Taddia, F.; Östlin, G.; Asadi, S.; Herrero-Illana, R.; Jensen, J. J.; Karhunen, K.; Lazarevic, S.; Varenius, E.; dos Santos, Paulo Guilherme; Seethapuram Sridhar, S.; Wallström, S. H. J.; Wiegert, J. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    We present ultraviolet (UV) observations of six nearby Type Ia supernovae (SNe Ia) obtained with the Hubble Space Telescope, three of which were also observed in the near-IR (NIR) with Wide-Field Camera 3. UV observations ...
  • The Fraction of Cool-core Clusters in X-Ray versus SZ Samples Using Chandra Observations 
    Andrade-Santos, F.; Jones, Christine; Forman, William R.; Lovisari, Lorenzo; Vikhlinin, Alexey; van Weeren, Reinout J.; Murray, Stephen S.; Arnaud, Monique; Pratt, Gabriel W.; Démoclès, J.; Kraft, Ralph; Mazzotta, P.; Böhringer, H.; Chon, Gayoung; Giacintucci, Simona; Clarke, Tracy E.; Borgani, S.; David, L.; Douspis, M.; Pointecouteau, E.; Dahle, Håkon; Brown, Shea; Aghanim, Nabila; Rasia, Elena (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    We derive and compare the fractions of cool-core clusters in the Planck Early Sunyaev–Zel'dovich sample of 164 clusters with $z\leqslant 0.35$ and in a flux-limited X-ray sample of 100 clusters with $z\leqslant 0.30$, using ...
  • Gravitational lensing reveals ionizing ultraviolet photons escaping from a distant galaxy 
    Rivera-Thorsen, Thøger Emil Juul; Dahle, Håkon; Chisholm, John; Florian, Michael K.; Gronke, Max Balthasar; Rigby, Jane R.; Gladders, Michael D.; Mahler, Guillaume; Sharon, Keren; Bayliss, Matthew B. (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)
    During the epoch of reionization, neutral gas in the early Universe was ionized by hard ultraviolet radiation emitted by young stars in the first galaxies. To do so, ionizing ultraviolet photons must escape from the host ...
  • High-redshift supernova rates measured with the gravitational telescope A 1689 
    Petrushevska, T.; Amanullah, R.; Goobar, A.; Fabbro, S.; Johansson, J.; Kjellsson, T.; Lidman, C.; Paech, K.; Richard, J.; Dahle, Håkon; Ferretti, R.; Kneib, J.-P.; Limousin, M.; Nordin, J.; Stanishev, V. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2016)
    Aims. We present a ground-based, near-infrared search for lensed supernovae behind the massive cluster Abell 1689 at z = 0.18, which is one of the most powerful gravitational telescopes that nature provides. Methods. Our ...
  • Hubble Constant Measurement from Three Large-separation Quasars Strongly Lensed by Galaxy Clusters 
    Napier, Kate; Sharon, Keren; Dahle, Håkon; Bayliss, Matthew; Gladders, Michael D.; Mahler, Guillaume; Rigby, Jane R.; Florian, Michael (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Tension between cosmic microwave background–based and distance ladder–based determinations of the Hubble constant H0 motivates the pursuit of independent methods that are not subject to the same systematic effects. A ...