PROGRAMA FONDECYT INFORME FINAL ETAPA 2015 COMISIÓN NACIONAL DE INVESTIGACION CIENTÍFICA Y TECNOLÓGICA VERSION OFICIAL FECHA: 14/03/2016 Nº PROYECTO : 1120741 DURACIÓN : 4 años AÑO ETAPA : 2015 TÍTULO PROYECTO : MICROLENSING IN LENSED QUASARS: PROBING THE LENS HALO AND THE SOURCE STRUCTURE DISCIPLINA PRINCIPAL : ASTRONOMIA GRUPO DE ESTUDIO : ASTRON.,COSMOL.Y PAR INVESTIGADOR(A) RESPONSABLE : VERONICA MOTTA CIFUENTES DIRECCIÓN : COMUNA : CIUDAD : REGIÓN : V REGION FONDO NACIONAL DE DESARROLLO CIENTIFICO Y TECNOLOGICO (FONDECYT) Moneda 1375, Santiago de Chile - casilla 297-V, Santiago 21 Telefono: 2435 4350 FAX 2365 4435 Email: [email protected] INFORME FINAL PROYECTO FONDECYT REGULAR MODIFICACIONES ACADÉMICAS El informe no presenta modificaciones académicas. PROJECT RESULTS: Describe the results of your research in reference to its original and/or modified Project objectives. The maximum length for this section is 5 pages (Arial or Verdana font, size 10). Summary of results per objectives: 1. Microlensing measurements: These measurements are obtained once a baseline of no-microlensing magnification is estimated using the narrow emission lines (NELs) observable in the optical range. If two or more emission line sufficiently separated in wavelength are available, the lens galaxy extinction among components can also be estimated directly. The com- parison of the NEL flux ratio among the different images of the lensed QSO and the photometric data from the literature (e.g. CASTLES) tell us whether the contin- uum of one image is microlensed at the epoch of the photometric observation and give us an estimate of the magnitude of the differential microlensing magnification cont line ∆m =(mB − mA) − (mB − mA) . In the cases where the contribution from the lens galaxy can be removed or are negligible (this is probably true in most cases for the blue part of the spectral range) this comparison is directly established from the continuum of the spectra. In order to obtain the sample required for a statistically significant study of microlens- ing, we selected 52 pairs of lensed quasars from CASTLES database. Roughly 30 pairs have been analyzed using spectra obtained from our observations (VLT, MMT, WHT) and from ESO VLT archive. Results for the systems HE0047-1756, HE0435- 1223, HE0512-3329, HS0818+1227, SBS0909+532, Q0957+561, SDSS1004+4112, SDSS1029+2623, HE1104-1805, SDSS1155+6346, Q2237+0305 have been published in Motta et al. 2012, Guerras et al. 2013a,b, Rojas et al. 2014, Jim´enez- Vicente et al. 2014. Some of the microlensing techniques applied for QSOs were also used in our Milky Way (MW), i.e. microlensing towards the center of the MW produced by compact objects. Results were published in Minniti et al. 2015. 2. Broad emission line microlensing: It has been suggested (Nemiroff 1988, Schneider & Wambsganss 1990, Abajas et al. 2002) that, depending on the structure of the broad emission line (BEL) region, mi- crolensing could modify the BEL profiles. Richard et al. (2004) were the first to show enhancements in the CIV BEL of SDSS1004+4112 system. The lack of microlensing 1 in the continuum was considered a serious drawback to interpret those enhance- ments as microlensing events. Our observations of this system not only confirm the presence of microlensing in the CIV BEL profile (Motta et al. 2012), but also show chromatic microlensing in the continuum. We have detected BEL microlens- ing in different emission lines for SDSS0806+2006, FBQS0951+2635, Q0957+561, SDSS1004+4112, HE1104-1805, SDSS1353+1138, SDSS1155+6346, WFI2033-4723 and the results were published in Motta et al. 2012, Guerras et al. 2013a,b. 3. Dust Extinction by the Lens Galaxy Dust extinction produced by the lens galaxy in the QSO continuum could be con- fused with microlensing. Thus, we used the core of emission lines to detect such extinction (these cores are not affected by microlensing). A very impressive demon- stration of this method is shown in Q0957+561 (Motta et al. 2012)wherewe detected the 2175A˚ bump associated to dust present in the lens galaxy. The first detection of the 2175A˚ feature beyond the Local Group was in SBS0909+532 (Motta et al. 2002, confirmed by Mediavilla et al. 2005), this detection is the second one. It is remarkable that the dust extinction curve fitted to the emission lines shifted -0.4 mag is in good agreement with the magnitude difference in the continuum (where the bump is also seen). 4 Structure of the Quasar Emitting Region: Chromatic microlensing can be used to measure the size and temperature of the emitting region. The accretion disk of the quasar can be modeled following Shakura & Sunayev (1973), which predict the size of the disk and the radial dependence of its surface temperature. Unfortunately, observational studies to tests this predictions are very limited due to the small angular size of the accretion disks. Lensed quasars offer the opportunity to resolve the accretion structure using the microlensing of the disk by the stars in the lens galaxy. If, as predicted by Shakura & Sunayev (1973), the size of the emitting region varies with wavelength, then microlensing magnifica- tion should be wavelength dependent (the so-called chromatic microlensing). We use microlensing simulations to estimate the size of the emitting region in those objects in which chromatic microlensing was detected. Results for objects HE0047- 1756, HE0435-1223, HE0512-3329, SBS0909+532, Q0957+561, SDSS1004+4112, SDSS1029+2623, HE1104-1805, SDSS1155+6346, Q2237+0305 were published in Motta et al. 2012, Rojas et al. 2014, Jim´enez-Vicente et al. 2014. 5 Improve in Gravitational Lensing Modelling: One of the key ingredients to produce microlensing simulations is the lens model. Although simple models are enough in most cases, we have encountered some prob- lems in a few systems. For example, SDSS1155+6346 has 2 images distorted by a 2 nearby cluster (Rojas et al. 2014) which makes modeling more complicated. Systems like SDSS1004+4112 and SDSS1029+2623 are QSO lensed by galaxy clusters. Thus, we are working on strong lens modelling were groups/clusters of galaxies are acting as lenses to improve our understanding of these cases. Some of the improvements we are introducing consist on including additional constrains to the strong lensing models (like dynamical mass, velocity dispersion) or studying a larger sample to obtain general properties of groups of galaxies. These results have been published in Mu˜noz et al. 2013, Fo¨ex et al. 2013, 2014, Gastaldello et al. 2014, Fern´andez-Trincado et al. 2014, L´opez-Cruz et al. 2014, Verdugo et al. 2014. 6 Cosmological Constraints using Gravitational Lensing: To estimate the size of the emitting region we need the distance to the lens and the source. The distance is obtained with the ΛCDM model. However, considering the increasing observational data on gravitational lens systems and the future discovery of a much more larger sample (Planck, SPT, ACT, LSST), we decided to explore its potential to contraint cosmological parameters. Results have been published in C´ardenas et al. 2013, Maga˜na, C´ardenas & Motta 2014, Maga˜na et al. 2015 and another one submitted (Bernal, C´ardenas & Motta 2016). Summary We have published 16 papers and presented results in 23 conferences. Three under- graduate students and one MSc. student successfully finished their thesis within our project. One PhD. student is doing her thesis under my supervision. 3 COOPERACIÓN INTERNACIONAL Nº Proyecto: 1120741 Nombre Colaborador (a) Extranjero (a): OMAR LOPEZ Afiliación Institucional Actual: INSTITUTO NACIONAL DE ASTROFISICA, OPTICA Y ELECTRONICA Fechas de estadía Desde :28/03/2015 Hasta :31/03/2015 Describa las actividades realizadas y resultados obtenidos. Destaque su contribución al logro de los objetivos del proyecto. Si es pertinente, indique las publicaciones conjuntas generadas, haciendo referencia a lo informado en la etapa Productos. Agregue en la etapa anexos la información necesaria. Dr. Omar-Lopez visit was related to the improvement of gravitational lens models (objective 5) by introducing dynamical constraints. During his short visit we also prepared a proposal for ALMA to observe a highly magnified lensed galaxy. Nº Proyecto: 1120741 Nombre Colaborador (a) Extranjero (a): EMILIO FALCO Afiliación Institucional Actual: HARVARD-SMITHSONIAN CENTER FOR ASTROPHYSICS Fechas de estadía Desde :30/10/2015 Hasta :14/11/2015 Describa las actividades realizadas y resultados obtenidos. Destaque su contribución al logro de los objetivos del proyecto. Si es pertinente, indique las publicaciones conjuntas generadas, haciendo referencia a lo informado en la etapa Productos. Agregue en la etapa anexos la información necesaria. Dr. Falco was not able to visit us during this period. Nº Proyecto: 1120741 Nombre Colaborador (a) Extranjero (a): TOMAS VERDUGO Afiliación Institucional Actual: CENTRO DE INVESTIGACIONES DE ASTRONOMIA Fechas de estadía Desde :30/10/2015 Hasta :14/11/2015 Describa las actividades realizadas y resultados obtenidos. Destaque su contribución al logro de los objetivos del proyecto. Si es pertinente, indique las publicaciones conjuntas generadas, haciendo referencia a lo informado en la etapa Productos. Agregue en la etapa anexos la información necesaria. Dr. Verdugo research visit was related to the improvement of gravitational lens models of several systems (objective 5). During his visit we reviewed 2 draft for articles in preparation (Verdugo et al. 2016 and Magaña et al. 2016) as well as proposals for future observations. PRODUCTOS