Blindly detecting orbital modulations of jets from merging supermassive black holes

In the last few years before merger, supermassive black hole binaries will rapidly inspiral and precess in a magnetic field imposed by a surrounding circumbinary disk. Multiple simulations suggest this relative motion will convert some of the local energy to a Poynting-dominated outflow, with a luminosity 10^{43} erg/s * (B/10^4 G)^2(M/10^8 Msun)^2 (v/0.4 c)^2, some of which may emerge as synchrotron emission at frequencies near 1 GHz where current and planned wide-field radio surveys will operate. On top of a secular increase in power on the gravitational wave inspiral timescale, orbital motion will produce significant, detectable modulations, both on orbital periods and (if black hole spins are not aligned with the binary's total angular momenta) spin-orbit precession timescales. Because the gravitational wave merger time increases rapidly with separation, we find vast numbers of these transients are ubiquitously predicted, unless explicitly ruled out (by low efficiency $\epsilon$) or obscured (by accretion geometry f_{geo}). If the fraction of Poynting flux converted to radio emission times the fraction of lines of sight accessible $f_{geo}$ is sufficiently large (f_{geo} \epsilon > 2\times 10^{-4} for a 1 year orbital period), at least one event is accessible to future blind surveys at a nominal 10^4 {deg}^2 with 0.5 mJy sensitivity. Our procedure generalizes to other flux-limited surveys designed to investigate EM signatures associated with many modulations produced by merging SMBH binaries.Comment: Submitted to ApJ. v1 original submission; v2 minor changes in response to refere

Constraints on the environment and energetics of the Broad-Line Ic SN2014ad from deep radio and X-ray observations

Broad-line type Ic Supernovae (BL-Ic SNe) are characterized by high ejecta velocity ($\gtrsim 10^4$ km s$^{-1}$) and are sometimes associated with the relativistic jets typical of long duration ($\gtrsim 2$ s) Gamma-Ray Bursts (L-GRBs). The reason why a small fraction of BL-Ic SNe harbor relativistic jets is not known. Here we present deep X-ray and radio observations of the BL-Ic SN2014ad extending from $13$ to $930$ days post explosion. SN2014ad was not detected at either frequency and has no observational evidence of a GRB counterpart. The proximity of SN2014ad ($d\sim 26$ Mpc) enables very deep constraints on the progenitor mass-loss rate $\dot{M}$ and on the total energy of the fast ejecta $E$. We consider two synchrotron emission scenarios for a wind-like circumstellar medium (CSM): (i) uncollimated non-relativistic ejecta, and (ii) off-axis relativistic jet. Within the first scenario our observations are consistent with GRB-less BL-Ic SNe characterized by a modest energy budget of their fast ejecta ($E \lesssim 10^{45}$ erg), like SNe 2002ap and 2010ay. For jetted explosions, we cannot rule out a GRB with $E \lesssim 10^{51}$ erg (beam-corrected) with a narrow opening angle ($\theta_j \sim 5^{\circ}$) observed moderately off-axis ($\theta_{\rm obs} \gtrsim 30^{\circ}$) and expanding in a very low CSM density ($\dot{M}$ $\lesssim 10^{-6}$ M$_{\odot}$ yr$^{-1}$). Our study shows that off-axis low-energy jets expanding in a low-density medium cannot be ruled out even in the most nearby BL-Ic SNe with extensive deep observations, and might be a common feature of BL-Ic SNe.Comment: 9 pages, 5 figures, accepted in Ap

Impact of post biomethanated spentwash on soil properties, nutrient uptake and yield of soybean – wheat cropping sequence

A field experiment was conducted on Sawargaon series of isohyperthermic family of Vertic haplustepts to study the effect of application of primary treated biomethanated spentwash (PBSW) through irrigation on soil properties, nutrient uptake and yield of soybean – wheat cropping sequence. The bulk density and hydraulic conductivity of soil were improved in 100% recommended dose (RD) of N through PBSW with and without P chemical fertilizer at soil depths of 0-15 and 15-30 cm. The lowest soil pH, calcium carbonate and highest electrical conductivity, organic carbon, available K, exchangeable sodium (Na), exchangeable sodium percentage (ESP), cation exchange capacity (CEC), sodium adsorption ratio (SAR) and pooled bacterial, fungal and actinomycetes populations in surface (0-15 cm) soil depth were observed in 100% RD of N through PBSW + with and without P chemical fertilizer at all three soil depths (0-15, 15-30 and 30-60 cm) over the other treatments. The highest pooled available soil P was recorded in 50% RD of N through PBSW application through irrigation and remaining N and P through chemical fertilizers in all three soil depths. The significantly highest total NPK uptake by cropping sequence and highest mean Benefit : Cost (B:C) ratio of soybean and wheat was recorded in 25 % RD of N through PBSW + remaining N and P through chemical fertilizers over the rest of the treatments. The 25 % N-recommended dose of soybean and wheat crop can be replaced by application of PBSW through irrigation in sequence without disturbing soils by salt load

Strain-Rate Frequency Superposition in Large-Amplitude Oscillatory Shear

In a recent work, Wyss, {\it et.al.} [Phys. Rev. Lett., {\bf 98}, 238303 (2007)] have noted a property of `soft solids' under oscillatory shear, the so-called strain-rate frequency superposition (SRFS). We extend this study to the case of soft solids under large-amplitude oscillatory shear (LAOS). We show results from LAOS studies in a monodisperse hydrogel suspension, an aqueous gel, and a biopolymer suspension, and show that constant strain-rate frequency sweep measurements with soft solids can be superimposed onto master curves for higher harmonic moduli, with the {\it same} shift factors as for the linear viscoelastic moduli. We show that the behavior of higher harmonic moduli at low frequencies in constant strain-rate frequency sweep measurements is similar to that at large strain amplitudes in strain-amplitude sweep tests. We show surface plots of the harmonic moduli and the energy dissipation rate per unit volume in LAOS for soft solids, and show experimentally that the energy dissipated per unit volume depends on the first harmonic loss modulus alone, in both the linear and the nonlinear viscoelastic regime.Comment: 10 pages, 25 figures, accepted for publication in Physical Review E. Incorporates referee comment

Dust in the wind: the role of recent mass loss in long gamma-ray bursts

We study the late-time (t>0.5 days) X-ray afterglows of nearby (z<0.5) long Gamma-Ray Bursts (GRB) with Swift and identify a population of explosions with slowly decaying, super-soft (photon index Gamma_x>3) X-ray emission that is inconsistent with forward shock synchrotron radiation associated with the afterglow. These explosions also show larger-than-average intrinsic absorption (NH_x,i >6d21 cm-2) and prompt gamma-ray emission with extremely long duration (T_90>1000 s). Chance association of these three rare properties (i.e. large NH_x,i, super-soft Gamma_x and extreme duration) in the same class of explosions is statistically unlikely. We associate these properties with the turbulent mass-loss history of the progenitor star that enriched and shaped the circum-burst medium. We identify a natural connection between NH_x,i Gamma_x and T_90 in these sources by suggesting that the late-time super-soft X-rays originate from radiation reprocessed by material lost to the environment by the stellar progenitor before exploding, (either in the form of a dust echo or as reprocessed radiation from a long-lived GRB remnant), and that the interaction of the explosion's shock/jet with the complex medium is the source of the extremely long prompt emission. However, current observations do not allow us to exclude the possibility that super-soft X-ray emitters originate from peculiar stellar progenitors with large radii that only form in very dusty environments.Comment: 6 pages, Submitted to Ap

Relativistic supernovae have shorter-lived central engines or more extended progenitors: the case of SN\,2012ap

Deep late-time X-ray observations of the relativistic, engine-driven, type Ic SN2012ap allow us to probe the nearby environment of the explosion and reveal the unique properties of relativistic SNe. We find that on a local scale of ~0.01 pc the environment was shaped directly by the evolution of the progenitor star with a pre-explosion mass-loss rate <5x10^-6 Msun yr-1 in line with GRBs and the other relativistic SN2009bb. Like sub-energetic GRBs, SN2012ap is characterized by a bright radio emission and evidence for mildly relativistic ejecta. However, its late time (t~20 days) X-ray emission is ~100 times fainter than the faintest sub-energetic GRB at the same epoch, with no evidence for late-time central engine activity. These results support theoretical proposals that link relativistic SNe like 2009bb and 2012ap with the weakest observed engine-driven explosions, where the jet barely fails to breakout. Furthermore, our observations demonstrate that the difference between relativistic SNe and sub-energetic GRBs is intrinsic and not due to line-of-sight effects. This phenomenology can either be due to an intrinsically shorter-lived engine or to a more extended progenitor in relativistic SNe.Comment: Version accepted to ApJ. Significantly broadened discussio

No X-rays from the very nearby Type Ia SN2014J: constraints on its environment

Deep X-ray observations of the post-explosion environment around the very nearby Type Ia SN\,2014J (Dl=3.5 Mpc) reveal no X-ray emission down to a luminosity L<7x10^{36} erg/s (0.3-10 keV) at t~20 days after the explosion. We interpret this limit in the context of Inverse Compton emission from upscattered optical photons by the supernova shock and constrain the pre-explosion mass-loss rate of the stellar progenitor system to be <10^{-9} M_sun yr-1 (for wind velocity v_w=100 km/s). Alternatively, the SN shock might be expanding into a uniform medium with density $n_CSM<3 cm-3. These results rule out single-degenerate (SD) systems with steady mass-loss until the terminal explosion and constrain the fraction of transferred material lost at the outer Lagrangian point to be <1%. The allowed progenitors are (i) WD-WD progenitors, (ii) SD systems with unstable hydrogen burning experiencing recurrent nova eruptions with recurrence time t<300 yrs and (iii) stars where the mass loss ceases before the explosion.Comment: 9 pages, Submitted to Ap

Impact of different levels of organic and inorganic fertilizers on growth, yield and quality of preseasonal sugarcane ratoon in Inceptisols

A field experiment was conducted at soil test crop response (STCR) correlation project farm of Mahatma Phule Krishi Vidyapeeth, Rahuri Maharashtra.The result showed that individual application of nitrogen (N), phosphorus(P),potassium(K) or organic nutrient sources (Farm yard manure) recorded less value of preseasonal sugarcane ratoon but the integration of both the sources showed significantly improved all the growth, yield and quality parameters of preseasonal sugarcane ratoon. The maximum number of internodes were ranged between 21-30 with mean of 25.42, number of leaves 6-10 with mean of 7.21, length of internodes 12.50-16.80 cm with mean of 14.41 cm, girth of internodes 11.30-13.10 cm with mean of 12.15 cm and height of millable cane 335-385 with mean of 351.75 cm, respectively were found higher with application of residual effect of 30 t ha-1 farm yard manure (FYM). However, the quality traits viz., brix ranged from 18.70 to 22.80 with mean of 19.87, pol per cent ranged from 15.81 to 18.41 per cent with mean of 17.53 per cent and commercial cane sugar (CCS) per cent from 9.39 to 12.09 per cent with mean of 10.76 per cent. The CCS yield was ranged between 9.58-16.30 MT ha-1 with mean value of 14.13 MT ha-1were enhanced considerably with residual 15 and 30 t FYM ha-1 blocks over without FYM. The application of organic and inorganic fertilizers will not only enhance the growth, yield and quality of preseasonal sugarcane ratoon but also conserve agro-ecosystem for sustainable crop production

Soil test crop response based Integrated plant nutrition system for desired yield target of preseasonal sugarcane ratoon on Inceptisols

Studies on Soil Test Crop Response based Integrated Plant Nutrition System (STCR - IPNS) were conducted adopting the Inductive cum Targeted yield model onInceptisols (VerticHaplustepts) in Rahuri, District Ahemadnagar, Maharashtra, India in order to develop fertilizer prescriptions through IPNS for the desired yield targets of preseasonal sugarcane ratoon. The field experiments were carried out with maize as gradient crop for plant cane and after harvest of plant cane, pre-seasonal sugarcane ratoon as test crop. Using the data on yield, initial soil test values on available nitrogen (N), phosphorus (P), potassium (K), doses of fertilizers and farmyard manure (FYM) applied and NPK uptake, the basic parameters viz., nutrient requirement, contribution from soil, fertilizers and FYM were computed. It was found that 1.56 kg N, 0.58 kg P and 1.04 kg K were required for producing one tonnemillable cane of preseasonal ratoon sugarcane. The per cent contributions of N, P and K from soil and FYM for preseasonal sugarcane ratoon were 37.65, 85.88 and 19.82 per cent and 11.83, 10.88 and 12.24 per cent, respectively. Making use of these basic parameters, fertilizer prescription equations were developed for pre-seasonal sugarcane ratoon (var. C0-94012) and an estimate of fertilizer doses formulated for a range of soil test values and desired yield targets under NPK alone and IPNS (NPK plus FYM)