C. M. O’Riordan, L. J. Oldham, A. Nersesian, T. Li, T. E. Collett, D. Sluse, B. Altieri, B. Clément, K. G. C. Vasan, S. Rhoades, Y. Chen, T. Jones, C. Adami, R. Gavazzi, S. Vegetti, D. M. Powell, J. A. Acevedo Barroso, I. T. Andika, R. Bhatawdekar, A. R. Cooray, G. Despali, J. M. Diego, L. R. Ecker, A. Galan, P. Gómez-Alvarez, L. Leuzzi, M. Meneghetti, R. B. Metcalf, M. Schirmer, S. Serjeant, C. Tortora, M. Vaccari, G. Vernardos, M. Walmsley, A. Amara, S. Andreon, N. Auricchio, H. Aussel, C. Baccigalupi, M. Baldi, A. Balestra, S. Bardelli, A. Basset, P. Battaglia, R. Bender, D. Bonino, E. Branchini, M. Brescia, J. Brinchmann, A. Caillat, S. Camera, V. Capobianco, C. Carbone, J. Carretero, S. Casas, F. J. Castander, M. Castellano, G. Castignani, S. Cavuoti, A. Cimatti, C. Colodro-Conde, G. Congedo, C. J. Conselice, L. Conversi, Y. Copin, L. Corcione, F. Courbin, H. M. Courtois, M. Cropper, A. Da Silva, H. Degaudenzi, G. De Lucia, A. M. Di Giorgio, J. Dinis, F. Dubath, C. A. J. Duncan, X. Dupac, S. Dusini, M. Farina, S. Farrens, F. Faustini, S. Ferriol, N. Fourmanoit, M. Frailis, E. Franceschi, M. Fumana, S. Galeotta, W. Gillard, B. Gillis, C. Giocoli, B. R. Granett, A. Grazian, F. Grupp, L. Guzzo, S. V. H. Haugan, J. Hoar, H. Hoekstra, W. Holmes, I. Hook, F. Hormuth, A. Hornstrup, P. Hudelot, K. Jahnke, M. Jhabvala, B. Joachimi, E. Keihänen, S. Kermiche, A. Kiessling, M. Kilbinger, R. Kohley, B. Kubik, M. Kümmel, M. Kunz, H. Kurki-Suonio, O. Lahav, R. Laureijs, D. Le Mignant, S. Ligori, P. B. Lilje, V. Lindholm, I. Lloro, G. Mainetti, E. Maiorano, O. Mansutti, O. Marggraf, K. Markovic, M. Martinelli, N. Martinet, F. Marulli, R. Massey, E. Medinaceli, S. Mei, M. Melchior, Y. Mellier, E. Merlin, G. Meylan, M. Moresco, L. Moscardini, R. Nakajima, R. C. Nichol, S.-M. Niemi, J. W. Nightingale, C. Padilla, S. Paltani, F. Pasian, K. Pedersen, W. J. Percival, V. Pettorino, S. Pires, G. Polenta, M. Poncet, L. A. Popa, L. Pozzetti, F. Raison, R. Rebolo, A. Renzi, J. Rhodes, G. Riccio, H.-W. Rix, E. Romelli, M. Roncarelli, E. Rossetti, B. Rusholme, R. Saglia, Z. Sakr, A. G. Sánchez, D. Sapone, B. Sartoris, P. Schneider, T. Schrabback, A. Secroun, G. Seidel, S. Serrano, C. Sirignano, G. Sirri, L. Stanco, J. Steinwagner, P. Tallada-Crespí, I. Tereno, R. Toledo-Moreo, F. Torradeflot, I. Tutusaus, L. Valenziano, T. Vassallo, G. Verdoes Kleijn, A. Veropalumbo, Y. Wang, J. Weller, A. Zacchei, G. Zamorani, E. Zucca, C. Burigana, P. Casenove, A. Mora, V. Scottez, M. Viel, M. Jauzac, H. Dannerbauer
{"title":"Euclid: A complete Einstein ring in NGC 6505⋆","authors":"C. M. O’Riordan, L. J. Oldham, A. Nersesian, T. Li, T. E. Collett, D. Sluse, B. Altieri, B. Clément, K. G. C. Vasan, S. Rhoades, Y. Chen, T. Jones, C. Adami, R. Gavazzi, S. Vegetti, D. M. Powell, J. A. Acevedo Barroso, I. T. Andika, R. Bhatawdekar, A. R. Cooray, G. Despali, J. M. Diego, L. R. Ecker, A. Galan, P. Gómez-Alvarez, L. Leuzzi, M. Meneghetti, R. B. Metcalf, M. Schirmer, S. Serjeant, C. Tortora, M. Vaccari, G. Vernardos, M. Walmsley, A. Amara, S. Andreon, N. Auricchio, H. Aussel, C. Baccigalupi, M. Baldi, A. Balestra, S. Bardelli, A. Basset, P. Battaglia, R. Bender, D. Bonino, E. Branchini, M. Brescia, J. Brinchmann, A. Caillat, S. Camera, V. Capobianco, C. Carbone, J. Carretero, S. Casas, F. J. Castander, M. Castellano, G. Castignani, S. Cavuoti, A. Cimatti, C. Colodro-Conde, G. Congedo, C. J. Conselice, L. Conversi, Y. Copin, L. Corcione, F. Courbin, H. M. Courtois, M. Cropper, A. Da Silva, H. Degaudenzi, G. De Lucia, A. M. Di Giorgio, J. Dinis, F. Dubath, C. A. J. Duncan, X. Dupac, S. Dusini, M. Farina, S. Farrens, F. Faustini, S. Ferriol, N. Fourmanoit, M. Frailis, E. Franceschi, M. Fumana, S. Galeotta, W. Gillard, B. Gillis, C. Giocoli, B. R. Granett, A. Grazian, F. Grupp, L. Guzzo, S. V. H. Haugan, J. Hoar, H. Hoekstra, W. Holmes, I. Hook, F. Hormuth, A. Hornstrup, P. Hudelot, K. Jahnke, M. Jhabvala, B. Joachimi, E. Keihänen, S. Kermiche, A. Kiessling, M. Kilbinger, R. Kohley, B. Kubik, M. Kümmel, M. Kunz, H. Kurki-Suonio, O. Lahav, R. Laureijs, D. Le Mignant, S. Ligori, P. B. Lilje, V. Lindholm, I. Lloro, G. Mainetti, E. Maiorano, O. Mansutti, O. Marggraf, K. Markovic, M. Martinelli, N. Martinet, F. Marulli, R. Massey, E. Medinaceli, S. Mei, M. Melchior, Y. Mellier, E. Merlin, G. Meylan, M. Moresco, L. Moscardini, R. Nakajima, R. C. Nichol, S.-M. Niemi, J. W. Nightingale, C. Padilla, S. Paltani, F. Pasian, K. Pedersen, W. J. Percival, V. Pettorino, S. Pires, G. Polenta, M. Poncet, L. A. Popa, L. Pozzetti, F. Raison, R. Rebolo, A. Renzi, J. Rhodes, G. Riccio, H.-W. Rix, E. Romelli, M. Roncarelli, E. Rossetti, B. Rusholme, R. Saglia, Z. Sakr, A. G. Sánchez, D. Sapone, B. Sartoris, P. Schneider, T. Schrabback, A. Secroun, G. Seidel, S. Serrano, C. Sirignano, G. Sirri, L. Stanco, J. Steinwagner, P. Tallada-Crespí, I. Tereno, R. Toledo-Moreo, F. Torradeflot, I. Tutusaus, L. Valenziano, T. Vassallo, G. Verdoes Kleijn, A. Veropalumbo, Y. Wang, J. Weller, A. Zacchei, G. Zamorani, E. Zucca, C. Burigana, P. Casenove, A. Mora, V. Scottez, M. Viel, M. Jauzac, H. Dannerbauer","doi":"10.1051/0004-6361/202453014","DOIUrl":null,"url":null,"abstract":"We report the discovery of a complete Einstein ring around the elliptical galaxy NGC 6505, at <i>z<i/> = 0.042. This is the first strong gravitational lens discovered in <i>Euclid<i/> and the first in an NGC object from any survey. The combination of the low redshift of the lens galaxy, the brightness of the source galaxy (<i>I<i/><sub>E<sub/> = 18.1 lensed, <i>I<i/><sub>E<sub/> = 21.3 unlensed), and the completeness of the ring make this an exceptionally rare strong lens, unidentified until its observation by <i>Euclid<i/>. We present deep imaging data of the lens from the <i>Euclid<i/> Visible Camera (VIS) and Near-Infrared Spectrometer and Photometer (NISP) instruments, as well as resolved spectroscopy from the <i>Keck<i/> Cosmic Web Imager (KCWI). The <i>Euclid<i/> imaging in particular presents one of the highest signal-to-noise ratio optical/near-infrared observations of a strong gravitational lens to date. From the KCWI data we measure a source redshift of <i>z<i/> = 0.406. Using data from the Dark Energy Spectroscopic Instrument (DESI) we measure a velocity dispersion for the lens galaxy of <i>σ<i/><sub>⋆<sub/> = 303 ± 15 km s<sup>−1<sup/>. We model the lens galaxy light in detail, revealing angular structure that varies inside the Einstein ring. After subtracting this light model from the VIS observation, we model the strongly lensed images, finding an Einstein radius of , corresponding to 2.1 kpc at the redshift of the lens. This is small compared to the effective radius of the galaxy, . Combining the strong lensing measurements with analysis of the spectroscopic data we estimate a dark matter fraction inside the Einstein radius of and a stellar initial mass-function (IMF) mismatch parameter of , indicating a heavier-than-Chabrier IMF in the centre of the galaxy.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"41 1","pages":""},"PeriodicalIF":5.4000,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Astronomy & Astrophysics","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1051/0004-6361/202453014","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
摘要
我们报告在z = 0.042的椭圆星系NGC 6505周围发现了一个完整的爱因斯坦环。这是在欧几里得发现的第一个强引力透镜,也是在任何巡天观测的NGC天体中发现的第一个强引力透镜。透镜星系的低红移、源星系的亮度(IE = 18.1有透镜,IE = 21.3无透镜)以及环的完整性,使它成为一个异常罕见的强透镜,在被欧几里得观测到之前一直没有被发现。我们展示了来自欧几里德可见光照相机(VIS)和近红外分光计和光度计(NISP)仪器的透镜深度成像数据,以及来自凯克宇宙网成像仪(KCWI)的分辨光谱数据。尤其是欧几里得成像,是迄今为止对强引力透镜进行的信噪比最高的光学/近红外观测之一。根据 KCWI 的数据,我们测得源红移为 z = 0.406。利用暗能量光谱仪(DESI)的数据,我们测得透镜星系的速度色散为σ⋆ = 303 ± 15 km s-1。我们建立了透镜星系光的详细模型,揭示了爱因斯坦环内部变化的角度结构。从 VIS 观测中减去这个光模型后,我们对强透镜图像进行建模,发现爱因斯坦半径为 ,相当于透镜红移时的 2.1 kpc。与星系的有效半径相比,这个半径很小。结合强透镜测量结果和光谱数据分析,我们估计爱因斯坦半径内的暗物质比例为 ,恒星初始质量函数(IMF)失配参数为 ,表明星系中心的IMF重于开普勒IMF。
We report the discovery of a complete Einstein ring around the elliptical galaxy NGC 6505, at z = 0.042. This is the first strong gravitational lens discovered in Euclid and the first in an NGC object from any survey. The combination of the low redshift of the lens galaxy, the brightness of the source galaxy (IE = 18.1 lensed, IE = 21.3 unlensed), and the completeness of the ring make this an exceptionally rare strong lens, unidentified until its observation by Euclid. We present deep imaging data of the lens from the Euclid Visible Camera (VIS) and Near-Infrared Spectrometer and Photometer (NISP) instruments, as well as resolved spectroscopy from the Keck Cosmic Web Imager (KCWI). The Euclid imaging in particular presents one of the highest signal-to-noise ratio optical/near-infrared observations of a strong gravitational lens to date. From the KCWI data we measure a source redshift of z = 0.406. Using data from the Dark Energy Spectroscopic Instrument (DESI) we measure a velocity dispersion for the lens galaxy of σ⋆ = 303 ± 15 km s−1. We model the lens galaxy light in detail, revealing angular structure that varies inside the Einstein ring. After subtracting this light model from the VIS observation, we model the strongly lensed images, finding an Einstein radius of , corresponding to 2.1 kpc at the redshift of the lens. This is small compared to the effective radius of the galaxy, . Combining the strong lensing measurements with analysis of the spectroscopic data we estimate a dark matter fraction inside the Einstein radius of and a stellar initial mass-function (IMF) mismatch parameter of , indicating a heavier-than-Chabrier IMF in the centre of the galaxy.
期刊介绍:
Astronomy & Astrophysics is an international Journal that publishes papers on all aspects of astronomy and astrophysics (theoretical, observational, and instrumental) independently of the techniques used to obtain the results.