- ID:
- ivo://CDS.VizieR/J/AJ/162/17
- Title:
- KMTNet, MOA and OGLE light curve of KMT-2019-BLG-0371
- Short Name:
- J/AJ/162/17
- Date:
- 16 Mar 2022 00:13:06
- Publisher:
- CDS
- Description:
- We show that the perturbation at the peak of the light curve of microlensing event KMT-2019-BLG-0371 is explained by a model with a mass ratio between the host star and planet of q~0.08. Due to the short event duration (t_E_~6.5days), the secondary object in this system could potentially be a massive giant planet. A Bayesian analysis shows that the system most likely consists of a host star with a mass M_h_=0.09_-0.05_^+0.14^Msun and a massive giant planet with a mass M_p_=7.70_-3.90_^+11.34^M_Jup_. However, the interpretation of the secondary as a planet (i.e., as having M_p_<13M_Jup_) rests entirely on the Bayesian analysis. Motivated by this event, we conduct an investigation to determine which constraints meaningfully affect Bayesian analyses for microlensing events. We find that the masses inferred from such a Bayesian analysis are determined almost entirely by the measured value of {theta}_E_ and are relatively insensitive to other factors such as the direction of the event (l, b), the lens-source relative proper motion {mu}_rel_, or the specific Galactic model prior.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/160/255
- Title:
- KMTNet & OGLE I-band photometry of KMT-2019-BLG-0842
- Short Name:
- J/AJ/160/255
- Date:
- 09 Mar 2022
- Publisher:
- CDS
- Description:
- We report the discovery of a cold planet with a very low planet/host mass ratio of q=(4.09{+/-}0.27)x10^-5^, which is similar to the ratio of Uranus/Sun (q=4.37x10^-5^) in the solar system. The Bayesian estimates for the host mass, planet mass, system distance, and planet-host projected separation are M_host_=0.76{+/-}0.40M{sun}, M_planet_=10.3{+/-}5.5M{Earth}, D_L_=3.3{+/-}1.3kpc, and a{perp}=3.3{+/-}1.4 au, respectively. The consistency of the color and brightness expected from the estimated lens mass and distance with those of the blend suggests the possibility that the most blended light comes from the planet host, and this hypothesis can be established if high-resolution images are taken during the next (2020) bulge season. We discuss the importance of conducting optimized photometry and aggressive follow-up observations for moderately or very high magnification events to maximize the detection rate of planets with very low mass ratios.
- ID:
- ivo://CDS.VizieR/J/A+A/628/A3
- Title:
- LAE z~3-7 luminosity functions
- Short Name:
- J/A+A/628/A3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Lyman-alpha luminosity function (LF) based on deep observations of four lensing clusters. The precise aim of the present study is to further constrain the abundance of Lyman-alpha emitters (LAEs) by taking advantage of the magnification provided by lensing clusters. We blindly selected a sample of 156 LAEs, with redshifts between 2.9<z<6.7 and magnification-corrected Lyman alpha luminosities in the range 39<LogL_Ly{alpha}_[erg/s]<43. The price to pay to benefit from magnification is a reduction of the effective volume of the survey, together with a more complex analysis procedure. To properly take into account the individual differences in detection conditions (including lensing configurations, spatial and spectral morphologies) when computing the LF, a new method based on the 1/Vmax approach was implemented. The LAE LF has been obtained in four different redshift bins with constraints down to logL_Ly{alpha}_=40.5. From our data only, no significant evolution of LF mean slope can be found. When performing a Schechter analysis including data from the literature to complete the present sample a steep faint-end slope was measured varying from {alpha}=-1.69^+0.08^_-0.08_ to {alpha}=-1.87^+0.12^_-0.12_ between the lowest and the highest redshift bins. The contribution of the LAE population to the star formation rate density at z~6 is ~<50% depending on the luminosity limit considered, which is of the same order as the Lyman-break galaxy (LBG) contribution. The evolution of the LAE contribution with redshift depends on the assumed escape fraction of Lyman-alpha photons, and appears to slightly increase with increasing redshift when this fraction is conservatively set to one.
- ID:
- ivo://CDS.VizieR/J/AJ/159/261
- Title:
- LC of microlensing event OGLE-2012-BLG-0838
- Short Name:
- J/AJ/159/261
- Date:
- 08 Dec 2021
- Publisher:
- CDS
- Description:
- We present the discovery of a planet on a very wide orbit in the microlensing event OGLE-2012-BLG-0838. The signal of the planet is well separated from the main peak of the event and the planet-star projected separation is found to be twice the Einstein ring radius, which corresponds to a projected separation of ~4au. Similar planets around low-mass stars are very hard to find using any technique other than microlensing. We discuss microlensing model fitting in detail and discuss the prospects for measuring the mass and distance of the lens system directly.
- ID:
- ivo://CDS.VizieR/J/AJ/161/293
- Title:
- LCs of OGLE-2018-BLG-0567 and OGLE-2018-BLG-0962
- Short Name:
- J/AJ/161/293
- Date:
- 10 Dec 2021
- Publisher:
- CDS
- Description:
- We present the analyses of two microlensing events, OGLE-2018-BLG-0567 and OGLE-2018-BLG-0962. In both events, the short-lasting anomalies were densely and continuously covered by two high-cadence surveys. The light-curve modeling indicates that the anomalies are generated by source crossings over the planetary caustics induced by planetary companions to the hosts. The estimated planet/host separation (scaled to the angular Einstein radius {theta}E) and mass ratio are (s, qx10^3^)=(1.81{+/-}0.02, 1.24{+/-}0.07) and (s, qx10^3^)=(1.25{+/-}0.03, 2.38{+/-}0.08), respectively. From Bayesian analyses, we estimate the host and planet masses as (M_h_, M_p_)=(0.25_-0.13_^+0.27^, M{odot}, 0.32_-0.17_^+0.34^, M_J_) and (M_h_, M_p_=(0.54_-0.28_^+0.33^, M{odot}, 1.34_-0.70_^+0.82^, M_J_), respectively. These planetary systems are located at a distance of 7.06_-1.15_^+0.93^kpc for OGLE-2018-BLG-0567 and 6.50_-1.75_^+1.06^kpc for OGLE-2018-BLG-0962, suggesting that they are likely to be near the Galactic bulge. The two events prove the capability of current high-cadence surveys for finding planets through the planetary-caustic channel. We find that most published planetary-caustic planets are found in Hollywood events in which the source size strongly contributes to the anomaly cross-section relative to the size of the caustic.
- ID:
- ivo://CDS.VizieR/J/ApJ/836/14
- Title:
- LCs & spectra of SDSS J1515+1511 lens system
- Short Name:
- J/ApJ/836/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze new optical observations of the gravitational lens system SDSS J1515+1511. These include a 2.6-year photometric monitoring with the Liverpool Telescope (LT) in the r band, as well as a spectroscopic follow-up with the LT and the Gran Telescopio Canarias (GTC). Our r-band LT light curves cover a quiescent microlensing period of the doubly imaged quasar at z_s_=2.049, which permits us to robustly estimate the time delay between the two images A and B: 211+/-5d (1{sigma} confidence interval; A is leading). Unfortunately, the main lensing galaxy (G1) is so faint and close to the bright quasar that it is not feasible to accurately extract its spectrum through the GTC data. However, assuming the putative redshift z_G1_=0.742, the GTC and LT spectra of the distant quasar are used to discuss the macrolens magnification, and the extinction and microlensing effects in G1. The new constraints on the time delay and macrolens magnification ratio essentially do not change previous findings on the mass scale of G1 and external shear, while the redshift of the lensing mass is found to be consistent with the assumed value of z_G1_. This is clear evidence that G1 is indeed located at z_G1_=0.742. From the GTC data, we also obtain the redshift of two additional objects (the secondary galaxy G2 and a new absorption system) and discuss their possible roles in the lens scenario.
- ID:
- ivo://CDS.VizieR/J/MNRAS/466/3088
- Title:
- Lensed and extended quasars
- Short Name:
- J/MNRAS/466/3088
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Wide-field photometric surveys enable searches of rare yet interesting objects, such as strongly lensed quasars or quasars with a bright host galaxy. Past searches for lensed quasars based on their optical and near-infrared properties have relied on photometric cuts and spectroscopic preselection (as in the Sloan Quasar Lens Search), or neural networks applied to photometric samples. These methods rely on cuts in morphology and colours, with the risk of losing many interesting objects due to scatter in their population properties, restrictive training sets, systematic uncertainties in catalogue-based magnitudes and survey-to-survey photometric variations. Here, we explore the performance of a Gaussian mixture model to separate point-like quasars, quasars with an extended host and strongly lensed quasars using grizpsf and model magnitudes and WISEW1, W2. The choice of optical magnitudes is due to their presence in all current and upcoming releases of wide-field surveys, whereas UV information is not always available. We then assess the contamination from blue galaxies and the role of additional features such as W3 magnitudes or psf-model terms as morphological information. As a demonstration, we conduct a search in a random 10 per cent of the SDSS footprint, and provide the catalogue of the 43 SDSS object with the highest 'lens' score in our selection that survive visual inspection, and are spectroscopically confirmed to host active nuclei. We inspect archival data and find images of 5/43 objects in the Hubble Legacy Archive, including two known lenses.
- ID:
- ivo://CDS.VizieR/J/A+A/616/A118
- Title:
- Lensed QSOs light curves & spectral monitoring
- Short Name:
- J/A+A/616/A118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the framework of the Gravitational LENses and DArk MAtter (GLENDAMA) project, we present a database of nine gravitationally lensed quasars (GLQs) that have two or four images brighter than r=20mag and are located in the northern hemisphere. This new database consists of a rich variety of follow-up observations included in the GLENDAMA global archive, which is publicly available online and contains 6557 processed astronomical frames of the nine lens systems over the period 1999-2016. In addition to the GLQs, our archive also incorporates binary quasars, accretion-dominated radio-loud quasars, and other objects, where about 50% of the non-GLQs were observed as part of a campaign to identify GLQ candidates. Most observations of GLQs correspond to an ongoing long-term macro-programme with 2-10m telescopes at the Roque de los Muchachos Observatory, and these data provide information on the distribution of dark matter at all scales. We outline some previous results from the database, and we additionally obtain new results for several GLQs that update the potential of the tool for astrophysical studies.
- ID:
- ivo://CDS.VizieR/J/A+A/551/A104
- Title:
- Lensed QSO UM673/Q0142-100 VRi light curves
- Short Name:
- J/A+A/551/A104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present four years of photometric observations of the doubly imaged quasar UM673, carried out in three filters (VRi) with the Danish 1.54m telescope at the La Silla Observatory. We studied the variations in flux and in color index of each lensed component as a function of time, and we obtained an independent estimation of the magnitude of the faint lens galaxy, showing that its contribution cannot be neglected.
- ID:
- ivo://CDS.VizieR/J/A+A/553/A121
- Title:
- 2 lensed quasars light curves
- Short Name:
- J/A+A/553/A121
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Within the framework of the COSMOGRAIL collaboration we present 7- and 8.5-year-long light curves and time-delay estimates for two gravitationally lensed quasars: SDSS J1206+4332 and HS 2209+1914. We monitored these doubly lensed quasars in the R-band using four telescopes: the Mercator, Maidanak, Himalayan Chandra, and Euler Telescopes, together spanning a period of 7 to 8.5 observing seasons from mid-2004 to mid-2011. The photometry of the quasar images was obtained through simultaneous deconvolution of these data. The time delays were determined from these resulting light curves using four very different techniques: a dispersion method, a spline fit, a regression difference technique, and a numerical model fit. This minimizes the bias that might be introduced by the use of a single method.
