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Search for intermediate mass black hole binaries in the first and second observing runs of the Advanced LIGO and Virgo network
Gravitational-wave astronomy has been firmly established with the detection of gravitational waves from the merger of ten stellar-mass binary black holes and a neutron star binary. This paper reports on the all-sky search for gravitational waves from intermediate mass black hole binaries in the first and second observing runs of the Advanced LIGO and Virgo network. The search uses three independent algorithms: two based on matched filtering of the data with waveform templates of gravitational-wave signals from compact binaries, and a third, model-independent algorithm that employs no signal model for the incoming signal. No intermediate mass black hole binary event is detected in this search. Consequently, we place upper limits on the merger rate density for a family of intermediate mass black hole binaries. In particular, we choose sources with total masses M=m1+m2ϵ[120,800] M and mass ratios q=m2/m1ϵ[0.1,1.0]. For the first time, this calculation is done using numerical relativity waveforms (which include higher modes) as models of the real emitted signal. We place a most stringent upper limit of 0.20 Gpc-3 yr-1 (in comoving units at the 90% confidence level) for equal-mass binaries with individual masses m1,2=100 M and dimensionless spins χ1,2=0.8 aligned with the orbital angular momentum of the binary. This improves by a factor of ∼5 that reported after Advanced LIGO's first observing run
Past and present cosmic structure in the SDSS DR7 main sample
We present a chrono-cosmography project, aiming at the inference of the four
dimensional formation history of the observed large scale structure from its
origin to the present epoch. To do so, we perform a full-scale Bayesian
analysis of the northern galactic cap of the Sloan Digital Sky Survey (SDSS)
Data Release 7 main galaxy sample, relying on a fully probabilistic, physical
model of the non-linearly evolved density field. Besides inferring initial
conditions from observations, our methodology naturally and accurately
reconstructs non-linear features at the present epoch, such as walls and
filaments, corresponding to high-order correlation functions generated by
late-time structure formation. Our inference framework self-consistently
accounts for typical observational systematic and statistical uncertainties
such as noise, survey geometry and selection effects. We further account for
luminosity dependent galaxy biases and automatic noise calibration within a
fully Bayesian approach. As a result, this analysis provides highly-detailed
and accurate reconstructions of the present density field on scales larger than
Mpc, constrained by SDSS observations. This approach also leads to
the first quantitative inference of plausible formation histories of the
dynamic large scale structure underlying the observed galaxy distribution. The
results described in this work constitute the first full Bayesian non-linear
analysis of the cosmic large scale structure with the demonstrated capability
of uncertainty quantification. Some of these results will be made publicly
available along with this work. The level of detail of inferred results and the
high degree of control on observational uncertainties pave the path towards
high precision chrono-cosmography, the subject of simultaneously studying the
dynamics and the morphology of the inhomogeneous Universe.Comment: 27 pages, 9 figure
The effect of different eLISA-like configurations on massive black hole parameter estimation
As the theme for the future L3 Cosmic Vision mission, ESA has recently chosen
the `Gravitational Wave Universe'. Within this call, a mission concept called
eLISA has been proposed. This observatory has a current initial configuration
consisting of 4 laser links between the three satellites, which are separated
by a distance of one million kilometers, constructing a single channel
Michelson interferometer. However, the final configuration for the observatory
will not be fixed until the end of this decade. With this in mind, we
investigate the effect of different eLISA-like configurations on massive black
hole detections. This work compares the results of a Bayesian inference study
of 120 massive black hole binaries out to a redshift of for a m
arm-length eLISA with four and six links, as well as a m
arm-length observatory with four links. We demonstrate that the original eLISA
configuration should allow us to recover the luminosity distance of the source
with an error of less than 10% out to a redshift of , and a sky error
box of out to . In contrast, both alternative
configurations suggest that we should be able to conduct the same parameter
recovery with errors of less than 10% in luminosity distance out to
and out to . Using the information from these
studies, we also infer that if we were able to construct a 2Gm, 6-link
detector, the above values would shift to for luminosity distance and
for sky error. While the final configuration will also be dependent
on both technological and financial considerations, our study suggests that
increasing the size of a two arm detector is a viable alternative to the
inclusion of a third arm in a smaller detector. More importantly, this work
further suggests no clear scientific loss between either choice.Comment: 9 pages, 5 figure
Gamma-Ray Bursts, witnessing the birth of stellar mass black holes
Gamma-ray bursts are associated with catastrophic cosmic events. They appear
when a new black hole, created after the explosion of a massive star or the
merger of two compact stars, quickly accretes the matter around it and ejects a
transient relativistic jet in our direction. This review discusses the various
types of gamma-ray bursts, their progenitors, their beaming and their rate in
the local universe. We emphasize the broad astrophysical interest of GRB
studies, and the crucial role of high-energy satellites as exclusive suppliers
of GRB alerts and initial locations.Comment: 8 pages, 2 figures, invited review at the conference "An INTEGRAL
view of the high-energy sky (the first 10 years) - 9th INTEGRAL Workshop and
celebration of the 10th anniversary of the launch" - to appear in Proceedings
of Science - PoS(INTEGRAL 2012)11
Detection of 1.6 × 10^(10) M_⊙ of Molecular Gas in the Host Galaxy of the z = 5.77 SDSS Quasar J0927+2001
We have detected emission by the CO(5-4) and (6-5) rotational transitions at z = 5.7722 ± 0.0006 from the host galaxy of the SDSS quasar J0927+2001 using the Plateau de Bure Interferometer. The peak line flux density for the CO(5-4) line is 0.72 ± 0.09 mJy, with a line FWHM = 610 ± 110 km s^(-1). The implied molecular gas mass is (1.6 ± 0.3) × 10^(10) M_⊙. We also detect the 90 GHz continuum at 0.12 ± 0.03 mJy, consistent with a 47 K dust spectrum extrapolated from higher frequencies. J0927+2001 is the second example of a huge molecular gas reservoir within the host galaxy of a quasar within 1 Gyr of the big bang. Observations of J0927+2001 are consistent with a massive starburst coeval with a bright quasar phase in the galaxy, suggesting the rapid formation of both a supermassive black hole through accretion, and the stellar host spheroid, at a time close to the end of cosmic reionization
Detection of M of molecular gas in the host galaxy of the SDSS quasar J0927+2001
We have detected emission by the CO 5-4 and 6-5 rotational transitions at from the host galaxy of the SDSS quasar J0927+2001 using
the Plateau de Bure interferometer. The peak line flux density for the CO 5-4
line is mJy, with a line FWHM = km s. The
implied molecular gas mass is M. We also
detect the 90 GHz continuum at mJy, consistent with a 47K dust
spectrum extrapolated from higher frequencies. J0927+2001 is the second example
of a huge molecular gas reservoir within the host galaxy of a quasar within 1
Gyr of the big bang. Observations of J0927+2001 are consistent with a massive
starburst coeval with a bright quasar phase in the galaxy, suggesting the rapid
formation of both a super-massive black hole through accretion, and the stellar
host spheroid, at a time close to the end of cosmic reionization.Comment: 12 pages, 2 figures, to appear in ApJ Letter
Chemical analysis and aqueous solution properties of Charged Amphiphilic Block Copolymers PBA-b-PAA synthesized by MADIX
We have linked the structural and dynamic properties in aqueous solution of
amphiphilic charged diblock copolymers poly(butyl acrylate)-b-poly(acrylic
acid), PBA-b-PAA, synthesized by controlled radical polymerization, with the
physico-chemical characteristics of the samples. Despite product imperfections,
the samples self-assemble in melt and aqueous solutions as predicted by
monodisperse microphase separation theory. However, the PBA core are abnormally
large; the swelling of PBA cores is not due to AA (the Flory parameter
chiPBA/PAA, determined at 0.25, means strong segregation), but to h-PBA
homopolymers (content determined by Liquid Chromatography at the Point of
Exclusion and Adsorption Transition LC-PEAT). Beside the dominant population of
micelles detected by scattering experiments, capillary electrophoresis CE
analysis permitted detection of two other populations, one of h-PAA, and the
other of free PBA-b-PAA chains, that have very short PBA blocks and never
self-assemble. Despite the presence of these free unimers, the self-assembly in
solution was found out of equilibrium: the aggregation state is history
dependant and no unimer exchange between micelles occurs over months
(time-evolution SANS). The high PBA/water interfacial tension, measured at 20
mN/m, prohibits unimer exchange between micelles. PBA-b-PAA solution systems
are neither at thermal equilibrium nor completely frozen systems: internal
fractionation of individual aggregates can occur.Comment: 32 pages, 16 figures and 4 tables submitted to Journal of Interface
and Colloidal Scienc
Higher harmonics increase LISA's mass reach for supermassive black holes
Current expectations on the signal to noise ratios and masses of supermassive
black holes which the Laser Interferometer Space Antenna (LISA) can observe are
based on using in matched filtering only the dominant harmonic of the inspiral
waveform at twice the orbital frequency. Other harmonics will affect the
signal-to-noise ratio of systems currently believed to be observable by LISA.
More significantly, inclusion of other harmonics in our matched filters would
mean that more massive systems that were previously thought to be {\it not}
visible in LISA should be detectable with reasonable SNRs. Our estimates show
that we should be able to significantly increase the mass reach of LISA and
observe the more commonly occurring supermassive black holes of masses More specifically, with the inclusion of all known harmonics LISA
will be able to observe even supermassive black hole coalescences with total
mass (and mass-ratio 0.1) for a low frequency
cut-off of with an SNR up to
at a distance of 3 Gpc. This is important from the astrophysical
viewpoint since observational evidence for the existence of black holes in this
mass range is quite strong and binaries containing such supermassive black
holes will be inaccessible to LISA if one uses as detection templates only the
dominant harmonic.Comment: minor corrections mad
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