1. Strongly Lensed Supernovae in Well-Studied Galaxy Clusters with the Vera C. Rubin ObservatoryTanja Petrushevska, 2020, original scientific article Abstract: Strong lensing by galaxy clusters can be used to significantly expand the survey reach, thus allowing observation of magnified high-redshift supernovae that otherwise would remain undetected. Strong lensing can also provide multiple images of the galaxies that lie behind the clusters. Detection of strongly lensed Type Ia supernovae (SNe Ia) is especially useful because of their standardizable brightness, as they can be used to improve either cluster lensing models or independent measurements of cosmological parameters. The cosmological parameter, the Hubble constant, is of particular interest given the discrepancy regarding its value from measurements with different approaches. Here, we explore the feasibility of the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) of detecting strongly lensed SNe in the field of five galaxy clusters (Abell 1689 and Hubble Frontier Fields clusters) that have well-studied lensing models. Considering the 88 systems composed of 268 individual multiple images in the five cluster fields, we find that the LSST will be sensitive to SNe Ia (SNe IIP) exploding in 41 (23) galaxy images. The range of redshift of these galaxies is between 1.01 < z < 3.05. During its 10 years of operation, LSST is expected to detect 0.2 ± 0.1 SN Ia and 0.9 ± 0.3 core collapse SNe. However, as LSST will observe many more massive galaxy clusters, it is likely that the expectations are higher. We stress the importance of having an additional observing program for photometric and spectroscopic follow-up of the strongly lensed SNe detected by LSST.
Found in: ključnih besedah
Keywords: supernovae, strong gravitational lensing, galaxy clusters
Published: 28.11.2020; Views: 1638; Downloads: 80
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3. VizieR Online Data Catalog: A 1689 HAWK-I J-band image (Petrushevska+, 2016)Tanja Petrushevska, complete scientific database or corpus Abstract: The NIR data were obtained with the High Acuity Wide field K-band imager mounted on the VLT (Programmes ID 082.A-0431, 0.83.A-0398, 090.A-0492, 091.A-0108, P.I. Goobar). The HAWK-I has an array of four 2048x2048 HgCdTe detectors covering a total area of 7.5'x7.5' with a sampling of 0.106"/pix per pixel. The chips are separated by a 15" gap.
Found in: ključnih besedah
Summary of found: ...Clusters: galaxy, Infrared sources...
Keywords: Clusters: galaxy, Infrared sources
Published: 23.01.2018; Views: 2900; Downloads: 0
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4. Supernovae seen through gravitational telescopesTanja Petrushevska, 2017, doctoral dissertation Abstract: Gravitational lenses such as galaxies and galaxy clusters, can magnify the flux of background galaxies. These galaxies at high redshift can host supernovae (SNe) which, thanks to the magnification boost due to lensing, can be observed, otherwise too faint to be detected by current telescopes. Under the right circumstances, the background galaxies may also have multiple images due to the strong lensing. Of particular interest is to detect lensed supernovae of type Ia (SNe Ia), because of their standard brightness. They could help improve lensing models and, if multiple images are observed, the Hubble constant can be measured independently.
In this thesis, we use galaxy clusters as gravitational telescopes to search for lensed SNe at high redshift. We performed ground-based, near-infrared and optical search campaigns towards the massive clusters Abell 1689 and 370, which are among the most powerful gravitational telescopes known. Our search resulted in the discovery of five photometrically classified, core- collapse SNe at redshifts of 0.671 < z < 1.703 with significant magnification from the cluster. Owing to the power of the lensing cluster, we calculated the volumetric core-collapse SN rates for 0.4 z < 2.9, and find good agreement with previous estimates and predictions from cosmic star formation history. During our survey, we also discovered two SNe Ia in A1689 cluster members, which allowed us to determine the cluster Ia rate. Furthermore, we discuss the expectations of finding lensed SNe at high redshift in simulated search campaigns that can be conducted with upcoming ground- and space-based telescopes.
Magnification from a galaxy lens also allows for detailed studies of the SN properties at high redshift that otherwise would not be possible. Spec- troscopic observations of lensed high-redshift SNe Ia are of particular interest since they can be used to test for evolution of the standard candle nature of these objects. However, if systematic redshift-dependent properties are found, their utility for future surveys could be challenged. We investigate whether the properties of the strongly lensed and very distant SN Ia PS1- 10afx at z = 1.4, deviates from the well-studied nearby and intermediate populations of normal SNe Ia. In other study, we report the discovery of the first resolved multiply-imaged gravitationally lensed SN Ia.
Found in: ključnih besedah
Summary of found: ...Gravitational lenses such as galaxies and galaxy clusters, can magnify the flux of background...
Keywords: supernovae, gravitational telescopes, galaxy clusters, lensed supernovae, strong lensing, astronomical surveys and telescopes
Published: 23.01.2018; Views: 3001; Downloads: 0
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5. High-redshift supernova rates measured with the gravitational telescope A1689Tanja Petrushevska, 2016, published scientific conference contribution abstract Abstract: 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 survey was based on multi-epoch J-band observations with the HAWK-I instrument on VLT, with supporting optical data from the Nordic Optical Telescope.
Results. Our search resulted in the discovery of five photometrically classified, core-collapse supernovae with high redshifts of
0.671 < z < 1.703 and magnifications in the range ∆m = −0.31 to −1.58 mag, as calculated from lensing models in the literature.
Owing to the power of the lensing cluster, the survey had the sensitivity to detect supernovae up to very high redshifts, z ∼ 3,
albeit for a limited region of space. We present a study of the core-collapse supernova rates for 0.4 ≤ z < 2.9, and find good
agreement with previous estimates and predictions from star formation history. During our survey, we also discovered two Type Ia
supernovae in A 1689 cluster members, which allowed us to determine the cluster Ia rate to be 0.14+0.19 ± 0.01 SNuB h2 (SNuB ≡ −0.09
10−12 SNe L−1 yr−1 ), where the error bars indicate 1σ confidence intervals, statistical and systematic, respectively. The cluster rate ⊙,B
normalized by the stellar mass is 0.10+0.13 ± 0.02 in SNuM h2 (SNuM ≡ 10−12 SNe M−1 yr−1). Furthermore, we explore the optimal −0.06 ⊙
future survey for improving the core-collapse supernova rate measurements at z 2 using gravitational telescopes, and for detections with multiply lensed images, and we find that the planned WFIRST space mission has excellent prospects.
Conclusions. Massive clusters can be used as gravitational telescopes to significantly expand the survey range of supernova searches, with important implications for the study of the high-z transient Universe.
Found in: ključnih besedah
Summary of found: ...supernova, gravitational telescope, galaxy clusters, Abell 1689, strong lensing...
Keywords: supernova, gravitational telescope, galaxy clusters, Abell 1689, strong lensing
Published: 26.01.2018; Views: 2553; Downloads: 0
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7. High redshift supernova rates measured with a gravitational telescopeTanja Petrushevska, 2015, published scientific conference contribution abstract Abstract: Supernovae (SNe) are one the most energetic phenomena in the Universe and have been extensively used for astrophysical and cosmological applications. For example, type Ia SNe as distance indicators tools have revealed the accelerating expansion of the universe, while core-collapse (CC) being directly related to the death of massive stars, they trace the star formation history. One of the challenges of SN research is the measurements of the SN rates, particularly at high-z where not many measurements exist. Possible approach to this problem is to use the magnification power of gravitational telescopes such as galaxy clusters. I will present our ground based near-infrared/optical search for gravitationally magnified supernovae behind the galaxy cluster A1689. Our search resulted in the discovery of five highly magnified candidates at high-z classified as CC SNe. We measure the first volumetric CC SN rates.
Found in: ključnih besedah
Summary of found: ...magnification power of gravitational telescopes such as galaxy clusters. I will present our ground based...
Keywords: supernova rates, gravitational telescopes, galaxy clusters
Published: 26.01.2018; Views: 2478; Downloads: 0
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9. Sensitivity of CTA to gamma-ray emission from the Perseus galaxy clusterJudit Pérez-Romero, published scientific conference contribution Abstract: In these proceedings we summarize the current status of the study of the sensitivity of the Cherenkov Telescope Array (CTA) to detect diffuse gamma-ray emission from the Perseus galaxy cluster. Gamma-ray emission is expected in galaxy clusters both from interactions of cosmic rays (CR) with the intra-cluster medium, or as a product of annihilation or decay of dark matter
(DM) particles in case they are weakly interactive massive particles (WIMPs). The observation of Perseus constitutes one of the Key Science Projects to be carried out by the CTA Consortium. In this contribution, we focus on the DM-induced component of the flux. OurDMmodelling includes the substructures we expect in the main halo which will boost the annihilation signal significantly. We adopt an ON/OFF observation strategy and simulate the expected gamma-ray signals. Finally we compute the expected CTA sensitivity using a likelihood maximization analysis including the most recent CTA instrument response functions. In absence of signal, we show that CTA will allow us to provide stringent and competitive constraints on TeV DM, especially for the case of
DM decay.
Found in: ključnih besedah
Summary of found: ...cluster. Gamma-ray emission is expected in galaxy clusters both from interactions of cosmic rays (CR)...
Keywords: dark matter, gamma-ray astronomy, galaxy clusters, cosmic rays and astroparticles
Published: 27.01.2023; Views: 188; Downloads: 7
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10. Classification of gamma-ray targets for velocity-dependent and subhalo-boosted dark-matter annihilationDavid Maurin, Julien Lavalle, Martin Stref, Judit Pérez-Romero, Gaetán Facchinetti, Thomas Lacroix, Miguel Sánchez-Conde, original scientific article Abstract: Gamma-ray observations have long been used to constrain the properties of dark matter (DM), with a strong focus on weakly interacting massive particles annihilating through velocity-independent processes. However, in the absence of clear-cut observational evidence for the simplest candidates, the interest of the community in more complex DM scenarios involving a velocity-dependent cross-section has been growing steadily over the past few years. We present the first systematic study of velocity-dependent DM annihilation (in particular p-wave annihilation and Sommerfeld enhancement) in a variety of astrophysical objects, not only including the well-studied Milky Way dwarf satellite galaxies, but nearby dwarf irregular galaxies and local galaxy clusters as well. Particular attention is given to the interplay between velocity dependence and DM halo substructure. Uncertainties related to halo mass, phase-space and substructure modelling are also discussed in this velocity-dependent context. We show that, for s-wave annihilation, extremely large subhalo boost factors are to be expected, up to 10^11 in clusters and up to 10^6–10^7 in dwarf galaxies where subhalos are usually assumed not to play an important role. Boost factors for p-wave annihilation are smaller but can still reach 10^3 in clusters. The angular extension of the DM signal is also significantly impacted, with e.g. the cluster typical emission radius increasing by a factor of order 10 in the s-wave case. We also compute the signal contrast of the objects in our sample with respect to annihilation happening in the Milky Way halo. Overall, we find that the hierarchy between the brightest considered targets depends on the specific details of the assumed particle-physics model.
Found in: ključnih besedah
Summary of found: ...but nearby dwarf irregular galaxies and local galaxy clusters as well. Particular attention is given...
Keywords: dark matter theory, dwarf galaxies, galaxy clusters, gamma-ray theory
Published: 27.01.2023; Views: 196; Downloads: 0
Fulltext (2,74 MB) |
