- ID:
- ivo://CDS.VizieR/J/ApJ/864/45
- Title:
- Survey of X-ray emission from superluminous SNe
- Short Name:
- J/ApJ/864/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results from a sensitive X-ray survey of 26 nearby hydrogen-poor superluminous supernovae (SLSNe-I) with Swift, Chandra, and XMM. This data set constrains the SLSN evolution from a few days until ~2000d after explosion, reaching a luminosity limit Lx~10^40^erg/s and revealing the presence of significant X-ray emission possibly associated with PTF 12dam. No SLSN-I is detected above Lx~10^41^erg/s, suggesting that the luminous X-ray emission Lx~10^45^erg/s associated with SCP 60F6 is not common among SLSNe-I. We constrain the presence of off-axis gamma-ray burst (GRB) jets, ionization breakouts from magnetar engines and the density in the sub-parsec environments of SLSNe-I through inverse Compton emission. The deepest limits rule out the weakest uncollimated GRB outflows, suggesting that if the similarity of SLSNe-I with GRB/SNe extends to their fastest ejecta, then SLSNe-I are either powered by energetic jets pointed far away from our line of sight ({theta}>30{deg}), or harbor failed jets that do not successfully break through the stellar envelope. Furthermore, if a magnetar central engine is responsible for the exceptional luminosity of SLSNe-I, our X-ray analysis favors large magnetic fields B>2x10^14^G and ejecta masses M_ej_>3M_{sun}_, in agreement with optical/UV studies. Finally, we constrain the pre-explosion mass-loss rate of stellar progenitors of SLSNe-I. For PTF 12dam we infer dM/dt<2x10^-5^M_{sun}_/yr, suggesting that the SN shock interaction with an extended circumstellar medium is unlikely to supply the main source of energy powering the optical transient and that some SLSN-I progenitors end their lives as compact stars surrounded by a low-density medium similar to long GRBs and type Ib/c SNe.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/181/62
- Title:
- Survey of young solar analogs
- Short Name:
- J/ApJS/181/62
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from an adaptive optics survey for substellar and stellar companions to Sun-like stars. The survey targeted 266 F5-K5 stars in the 3Myr-3Gyr age range with distances of 10-190pc. Results from the survey include the discovery of two brown dwarf companions (HD 49197B and HD 203030B), 24 new stellar binaries, and a triple system. We infer that the frequency of 0.012-0.072M_{sun}_ brown dwarfs in 28-1590AU orbits around young solar analogs is 3.2^+3.1^_-2.7_% (2{sigma} limits). The result demonstrates that the deficiency of substellar companions at wide orbital separations from Sun-like stars is less pronounced than in the radial velocity "brown dwarf desert." We infer that the mass distribution of companions in 28-1590AU orbits around solar-mass stars follows a continuous dN/dM_2_{prop.to}M^-0.4^_2_ relation over the 0.01-1.0M_{sun}_ secondary mass range. While this functional form is similar to that for isolated objects less than 0.1M_{sun}_, over the entire 0.01-1.0M_{sun}_ range, the mass functions of companions and of isolated objects differ significantly. Based on this conclusion and on similar results from other direct imaging and radial velocity companion surveys in the literature, we argue that the companion mass function follows the same universal form over the entire range between 0 and 1590AU in orbital semimajor axis and ~0.01-20M_{sun}_ in companion mass. In this context, the relative dearth of substellar versus stellar secondaries at all orbital separations arises naturally from the inferred form of the companion mass function.
- ID:
- ivo://CDS.VizieR/J/ApJS/219/27
- Title:
- Surveys of asteroid rotation periods using iPTF
- Short Name:
- J/ApJS/219/27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Two dedicated asteroid rotation-period surveys have been carried out in the R band with ~20 minute cadence using the intermediate Palomar Transient Factory (iPTF) during 2014 January 6-9 and February 20-23. The total survey area covered 174deg^2^ in the ecliptic plane. Reliable rotation periods for 1438 asteroids are obtained from a larger data set of 6551 mostly main-belt asteroids, each with >=10 detections. Analysis of 1751, PTF-based, reliable rotation periods clearly shows the spin barrier at ~2hr for rubble-pile asteroids. We found a new large super-fast rotator, 2005 UW163, and another five candidates as well. For asteroids of 3<D<15km, our spin-rate distribution shows a number decrease along with frequency after 5 rev/day, which is consistent with the results of the Asteroid Light Curve Database. The discrepancy between our work and that of Pravec et al. (update 2014 April 20) comes mainly from asteroids with {Delta}_m_<0.2mag, which could be the result of different survey strategies. For asteroids with D<3km, we see a significant number drop at f=6rev/day. The relatively short YORP effect timescale for small asteroids could have spun up those elongated objects to reach their spin-rate limit resulting in breakup to create such a number deficiency. We also see that the C-type asteroids show a smaller spin-rate limit than the S-type, which agrees with the general impression that C-type asteroids have a lower bulk density than S-type asteroids.
- ID:
- ivo://CDS.VizieR/J/MNRAS/430/60
- Title:
- Suzaku view of highly ionized outflows in AGN
- Short Name:
- J/MNRAS/430/60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a new spectroscopic study of Fe K-band absorption in active galactic nuclei (AGN). Using data obtained from the Suzaku public archive we have performed a statistically driven blind search for FeXXV He{alpha} and/or FeXXVI Ly{alpha} absorption lines in a large sample of 51 Type 1.0-1.9 AGN. Through extensive Monte Carlo simulations we find that statistically significant absorption is detected at E>~6.7keV in 20/51 sources at the P_MC_>=95% level, which corresponds to ~40% of the total sample. In all cases, individual absorption lines are detected independently and simultaneously amongst the two (or three) available X-ray imaging spectrometer detectors, which confirms the robustness of the line detections. The most frequently observed outflow phenomenology consists of two discrete absorption troughs corresponding to FeXXV He{alpha} and FeXXVI Ly{alpha} at a common velocity shift. From xstar fitting the mean column density and ionization parameter for the FeK absorption components are log(N_H_/cm^2^)~23 and log({xi}/erg/cm/s)~4.5, respectively. Measured outflow velocities span a continuous range from <1500km/s up to ~100000km/s, with mean and median values of ~0.1c and ~0.056c, respectively. The results of this work are consistent with those recently obtained using XMM-Newton and independently provides strong evidence for the existence of very highly ionized circumnuclear material in a significant fraction of both radio-quiet and radio-loud AGN in the local universe.
18425. SV Cam BVR light curves
- ID:
- ivo://CDS.VizieR/J/A+A/376/158
- Title:
- SV Cam BVR light curves
- Short Name:
- J/A+A/376/158
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New BVR light curves and times of minimum light for the short period RS CVn system SV Cam were analysed to derive the physical parameters of the system and the parameters of the third body orbit. The light curves obtained at the TUEBITAK National Observatory during two nights in 2000 show considerable asymmetry and night-to-night variations. The analysis of the light curves is made using Djurasevic's inverse problem method. The Roche model with spotted areas on the hotter primary component yields a good fit to observations. The extensive series of published photoelectric minima times indicate that the eclipsing pair orbits around the common mass center of the triple system with a period of 41.32yr.
- ID:
- ivo://CDS.VizieR/J/A+A/406/193
- Title:
- SV Cam BVR light curves in Feb. 2001 - March 2002
- Short Name:
- J/A+A/406/193
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the analysis of new BVR light curves for the active star SV Cam. The Roche model with spotted areas on the hotter primary component fits satisfactorily all filter observations yielding two spots in intermediate latitudes and covering about 1.5% each of the stellar surface. Both are ~1000K cooler than surrounding photosphere. The comparison with an earlier season (January/February 2000) suggests that the spots probably evolved in area longitude and latitude but basic and preferred orientation from previous season is confirmed. The comparison stars were SAO 1045 (standard) and SAO 1030 (check).
- ID:
- ivo://CDS.VizieR/J/AN/325/424
- Title:
- SV Cam VB differential photometry
- Short Name:
- J/AN/325/424
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present analysis and spot solutions based on yet unpublished B and V photoelectric observations on the active binary system SV Cam, carried out at Piszkesteto Mountain Station of Konkoly Observatory Budapest. The present spot solutions are based on the observed light curves in September 1993 and July 1994. Comparison of recent and older spot solutions - taken from the literature - suggests long term differences, but these divergences might be caused by some differences of the applied computational methods.
- ID:
- ivo://CDS.VizieR/J/A+A/452/1113
- Title:
- S V effective collision strengths
- Short Name:
- J/A+A/452/1113
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Effective collision strengths are presented in this table for all the transitions among the 26 fine-structure levels arising from the 14 lowest LS states of S V, i.e. those with configurations: (2p^6^)3s^2^, 3s3p, 3p^2^, 3s3d, 3s4s, 3p3d. The effective collision strengths have been calculated using the R-matrix method. Each fine-structure level is assigned an index number ranging from 1 to 26, which are noted in the paper as Table 5. The index values are used here in Table 7 to refer to particular transitions, eg. Index 2-8 denotes the 2p(6)3s3p 3PO(J=0)- 2p(6)3p^2^ 3PE(J=1) transition. The effective collision strengths for each transition are presented for electron temperatures ranging from log10(T)=4.0 to log10(T)=6.0 in steps of 0.1.
- ID:
- ivo://CDS.VizieR/J/MNRAS/462/2747
- Title:
- S4 1030+61 VLBA observations, 2009-2014
- Short Name:
- J/MNRAS/462/2747
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the parsec-scale multifrequency properties of the quasar S4 1030+61 during a prolonged radio and {gamma}-ray activity. Observations were performed within Fermi {gamma}-ray telescope, Owens Valley Radio Observatory 40-m telescope and MOJAVE Very Long Baseline Array (VLBA) monitoring programmes, covering five years from 2009. The data are supplemented by four-epoch VLBA observations at 5, 8, 15, 24 and 43GHz, which were triggered by the bright {gamma}-ray flare, registered in the quasar in 2010. The S4 1030+61 jet exhibits an apparent superluminal velocity of (6.4+/-0.4)c and does not show ejections of new components in the observed period, while decomposition of the radio light curve reveals nine prominent flares. The measured variability parameters of the source show values typical for Fermi-detected quasars. Combined analysis of radio and {gamma}-ray emission implies a spatial separation between emitting regions at these bands of about 12pc and locates the {gamma}-ray emission within a parsec from the central engine. We detected changes in the value and direction of the linear polarization and the Faraday rotation measure. The value of the intrinsic brightness temperature of the core is above the equipartition state, while its value as a function of distance from the core is well approximated by the power law. Altogether these results show that the radio flaring activity of the quasar is accompanied by injection of relativistic particles and energy losses at the jet base, while S4 1030+61 has a stable, straight jet well described by standard conical jet theories.
- ID:
- ivo://CDS.VizieR/J/A+A/601/A12
- Title:
- S5 0716+714 VLBI K- and Q-band variability
- Short Name:
- J/A+A/601/A12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This study aims to search for the existence of intraday variability (IDV) of BL Lac object S5 0716+714 at high radio frequencies for which the interstellar scintillation effect is not significant. Using the 21-m radio telescope of the Korean VLBI Network (KVN), we present results of multi-epoch simultaneous dual-frequency radio observations. Single-dish observations of S5 0716+714 were simultaneously conducted at 21.7GHz (K-band) and 42.4GHz (Q-band), with a high cadence of 30-60min intervals. We observed four epochs between December 2009 and June 2010. Over the whole set of observation epochs, S5 0716+714 showed significant inter-month variations in flux density at both the K- and Q-bands, with modulation indices of approximately 19% for the K-band and approximately 36% for the Q-band. In all epochs, no clear intraday variability was detected at either frequency. The source shows monotonic flux density increase in epochs 1 and 3 and monotonic flux density decrease in epochs 2 and 4. In the flux density increasing phases, the flux densities at the Q-band increase more rapidly. In the decreasing phase, no significant flux density difference is seen at the two frequencies. The situation could be different close to flux density peaks that we did not witness in our observations. We find an inverted spectrum with mean spectral indices, {bar}{alpha}(S_{nu}_{prop.to}{nu}^-{alpha}^), of -0.57+/-0.13 in epoch 1 and -0.15+/-0.11 in epoch 3. On the other hand, we find relatively steep indices of +0.24+/-0.14 and +0.17+/-0.18 in epochs 2 and 4, respectively. We conclude that the frequency dependence of the variability and the change of the spectral index are caused by source-intrinsic effects rather than by any extrinsic scintillation effect.