Remnant Mass Research Articles

In-medium P-wave quarkonium from the complex lattice QCD potential

We extend our lattice QCD potential based study arXiv:1509.07366 (JHEP 1512 (2015) 101) of the in-medium properties of heavy quark bound states to P-wave bottomonium and charmonium. Similar to the behavior found in the S-wave channel their spectra show a characteristic broadening, as well as mass shifts to lower energy with increasing temperature. In contrast to the S-wave states, finite angular momentum leads to the survival of spectral peaks even at temperatures, where the continuum threshold reaches below the bound state remnant mass. We elaborate on the ensuing challenges in defining quarkonium dissolution, present estimates of melting temperatures for the spin averaged $\chi_b$ and $\chi_c$ states and contrast the findings to recent direct lattice NRQCD studies of P-wave quarkonium. As an application to heavy-ion collisions we estimate the contribution of feed down to S-wave quarkonium through the P-wave states after freezeout.

New models for the evolution of central stars of planetary nebulae: Faster and Brighter

AbstractThe post-asymptotic giant branch (AGB) phase is arguably one of the least understood phases of the evolution of low- and intermediate- mass stars. The recent post-AGB evolutionary sequences computed by Miller Bertolami (2016) are at least three to ten times faster than those previously published by Vassiliadis & Wood (1994) and Blöcker (1995) which have been used in a large number of studies. This is true for the whole mass and metallicity range. The new models are also ~0.1–0.3 dex brighter than the previous models with similar remnant masses. In this short article we comment on the main reasons behind these differences, and discuss possible implications for other studies of post-AGB stars or planetary nebulae.

Mass and metallicity requirement in stellar models for galactic chemical evolution applications

We used a one-zone chemical evolution model to address the question of how many masses and metallicities are required in grids of massive stellar models in order to ensure reliable galactic chemical evolution predictions. We used a set of yields that includes seven masses between 13 and 30 Msun, 15 metallicities between 0 and 0.03 in mass fraction, and two different remnant mass prescriptions. We ran several simulations where we sampled subsets of stellar models to explore the impact of different grid resolutions. Stellar yields from low- and intermediate-mass stars and from Type Ia supernovae have been included in our simulations, but with a fixed grid resolution. We compared our results with the stellar abundances observed in the Milky Way for O, Na, Mg, Si, Ca, Ti, and Mn. Our results suggest that the range of metallicity considered is more important than the number of metallicities within that range, which only affects our numerical predictions by about 0.1 dex. We found that our predictions at [Fe/H] < -2 are very sensitive to the metallicity range and the mass sampling used for the lowest metallicity included in the set of yields. Variations between results can be as high as 0.8 dex, for any remnant mass prescription. At higher [Fe/H], we found that the required number of masses depends on the element of interest and on the remnant mass prescription. With a monotonic remnant mass prescription where every model explodes as a core-collapse supernova, the mass resolution induces variations of 0.2 dex on average. But with a remnant mass prescription that includes islands of non-explodability, the mass resolution can cause variations of about 0.2 to 0.7 dex depending on the choice of metallicity range. With such a prescription, explosive or non-explosive models can be missed if not enough masses are selected, resulting in over- or under-estimations of the mass ejected by massive stars.

The evolution and fate of super-Chandrasekhar mass white dwarf merger remnants

We present stellar evolution calculations of the remnant of the merger of two carbon-oxygen white dwarfs (CO WDs). We focus on cases that have a total mass in excess of the Chandrasekhar mass. After the merger, the remnant manifests as an $L \sim 3 \times 10^4 L_\odot$ source for $\sim 10^4$ yr. A dusty wind may develop, leading these sources to be self-obscured and to appear similar to extreme AGB stars. Roughly $\sim 10$ such objects should exist in the Milky Way and M31 at any time. As found in previous work, off-center carbon fusion is ignited within the merger remnant and propagates inward via a carbon flame, converting the WD to an oxygen-neon (ONe) composition. By following the evolution for longer than previous calculations, we demonstrate that after carbon-burning reaches the center, neutrino-cooled Kelvin-Helmholtz contraction leads to off-center neon ignition in remnants with masses $\ge 1.35 M_\odot$. The resulting neon-oxygen flame converts the core to a silicon WD. Thus, super-Chandrasekhar WD merger remnants do not undergo electron-capture induced collapse as traditionally assumed. Instead, if the remnant mass remains above the Chandrasekhar mass, we expect that it will form a low-mass iron core and collapse to form a neutron star. Remnants that lose sufficient mass will end up as massive, isolated ONe or Si WDs.

Constraints on rainbow gravity functions from black-hole thermodynamics

In this paper, we investigate the thermodynamic properties of black holes in the framework of rainbow gravity. By considering rainbow functions in the metric of Schwarzschild and Reissner-Nordström black holes, remnant and critical masses are found to exist. Demanding the universality of logarithmic corrections to the semi-classical area law for the entropy leads to constraining the form of the rainbow functions. The mass output and the radiation rate for these constrained form of rainbow functions have been computed for different values of the rainbow parameter η and have striking similarity to those derived from the generalized uncertainty principle.

Structure of stable binary neutron star merger remnants: A case study

In this work, we study the merger of two neutron stars with a gravitational mass of $1.4\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$ each, employing the Shen-Horowitz-Teige equation of state. This equation of state is a corner case, allowing the formation of a stable neutron star with the given total baryonic mass of $3.03\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$. We investigate in unprecedented detail the structure of the remnant, in particular the mass distribution, the thermal structure, and the rotation profile. We also compute fluid trajectories both inside the remnant and those relevant for the formation of the disk. We find a peanut-shaped fluid flow inside the remnant following a strong $m=2$ perturbation. Moreover, the flow is locally compressive, causing the appearance of dynamic hot spots. Further, we introduce new diagnostic measures that are easy to implement in numeric simulations and that allow one to quantify mass and compactness of merger remnants in a well-defined way. As in previous studies of supra- and hypermassive stars, we find a remnant with a slowly rotating core and an outer envelope rotating at nearly Keplerian velocity. We compute a Tolman-Oppenheimer-Volkoff star model which agrees well with that of the remnant in the core, while the latter possesses extensive outer layers rotating close to Kepler velocity. Finally, we extract the gravitational wave signal and discuss the detectability with modern observatories. This study has implications for the interpretation of gravitational wave detections from the postmerger phase and is relevant for short gamma-ray burst models.

A stellar-mass black hole population in the globular cluster NGC 6101?

Dalessandro et al. observed a similar distribution for blue straggler stars and main-sequence turn-off stars in the Galactic globular cluster NGC 6101, and interpreted this feature as an indication that this cluster is not mass-segregated. Using direct N-body simulations, we find that a significant amount of mass segregation is expected for a cluster with the mass, radius and age of NGC 6101. Therefore, the absence of mass segregation cannot be explained by the argument that the cluster is not yet dynamically evolved. By varying the retention fraction of stellar-mass black holes, we show that segregation is not observable in clusters with a high black hole retention fraction (>50% after supernova kicks and >50% after dynamical evolution). Yet all model clusters have the same amount of mass segregation in terms of the decline of the mean mass of stars and remnants with distance to the centre. We also discuss how kinematics can be used to further constrain the presence of a stellar-mass black hole population and distinguish it from the effect of an intermediate-mass black hole. Our results imply that the kick velocities of black holes are lower than those of neutron stars. The large retention fraction during its dynamical evolution can be explained if NGC 6101 formed with a large initial radius in a Milky Way satellite.

A high-yield double-purification proteomics strategy for the identification of SUMO sites.

The small ubiquitin-like modifier (SUMO) is a protein modifier that is post-translationally coupled to thousands of lysines in more than a thousand proteins. An understanding of which lysines are modified by SUMO is critical in unraveling its function as a master regulator of all nuclear processes, as well as its involvement in diseases such as cancer. Here we describe a protocol for the lysine-deficient (K0) method for efficient identification of SUMOylated lysines by mass spectrometry (MS). To our knowledge, the K0 method is the only currently available method that can routinely identify >1,000 SUMO sites in mammalian cells under standard growth conditions. The K0 strategy relies on introducing a His10-tagged SUMO wherein all lysines have been substituted to arginines. Lysine deficiency renders the SUMO immune to digestion by the endoproteinase Lys-C, which in turn allows for stringent and high-yield tandem purification through the His10 tag. In addition, the His10-tagged SUMO also contains a C-terminal Q87R mutation, which accommodates generation of SUMO-site peptides with a QQTGG mass remnant after digestion with trypsin. This remnant possesses a unique mass signature and readily generates diagnostic ions in the fragment ion scans, which increases SUMO-site identification confidence. The K0 method can be applied in any mammalian cell line or in any model system that allows for integration of the K0-SUMO construct. From the moment of cell lysis, the K0 method takes ∼7 d to perform.

Erratum: Modeling the remnant mass, spin, and recoil from unequal-mass, precessing black-hole binaries: The intermediate mass ratio regime [Phys. Rev. D92, 024022 (2015)

The fits presented in the paper had an error in ${L}_{\mathrm{isco}}$ and were also not optimized for the aligned spin case. Of these two, the latter has a larger effect when using the formula for extrapolation. In addition, there were errors in the remnant spins obtained from the radiated angular momentum in Table XVIII.

The role of postoperative Tc-99m pertechnetate scintigraphy in estimation of remnant mass and prediction of successful ablation in patients with differentiated thyroid cancer.

Surgery and radioactive iodine (RAI) ablation constitute the mainstay of the treatment of differentiated thyroid carcinoma (DTC). In this study, we aimed to evaluate the diagnostic value of postoperative early Tc-99m pertechnetate scanning to detect remnant thyroid tissue and predict ablation success. DTC patients evaluated with postoperative Tc-99m pertechnetate scintigraphy and treated with RAI between January 2007 and December 2014 were recruited. The results of Tc-99m pertechnetate scanning were compared with therapeutic I-131 whole-body scanning (TxWBS) and diagnostic I-131 whole-body scanning (DxWBS) performed 6-9 months after RAI. There were 154 (21.5%) male and 563 (78.5%) female patients, with a mean age of 49.11±12.35 years. Postoperative Tc-99m pertechnetate scanning was positive in 499 patients (69.6%) and negative in 218 (30.4%) patients. There were 673 (93.9%) patients with a positive TxWBS scan and 44 (6.1%) patients with negative TxWBS scan. Considering TxWBS as the standard test, sensitivity, specificity, positive predictive value, and negative predictive value of Tc-99m pertechnetate scanning were 72.2, 70.5, 97.4, and 14.2%, respectively. DxWBS was positive in 57 (9.0%) and negative in 564 (91%) patients. Ablation dose was higher and preablation thyroglobulin was lower in patients with negative DxWBS (P=0.001 and 0.04, respectively). Overall, 171 (92.9%) of 184 patients with negative Tc-99m pertechnetate had negative DxWBS. Postoperative Tc-99m pertechnetate scintigraphy has a high positive predictive value to detect remnant tissue in patients with DTC. Although negative Tc-99m pertechnetate scanning does not indicate removal of all thyroid tissue, it is related to successful ablation in more than 90% of patients.

Tests of General Relativity with GW150914.

The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant's mass and spin, as determined from the low-frequency (inspiral) and high-frequency (postinspiral) phases of the signal, are mutually consistent with the binary black-hole solution in general relativity. Furthermore, the data following the peak of GW150914 are consistent with the least-damped quasinormal mode inferred from the mass and spin of the remnant black hole. By using waveform models that allow for parametrized general-relativity violations during the inspiral and merger phases, we perform quantitative tests on the gravitational-wave phase in the dynamical regime and we determine the first empirical bounds on several high-order post-Newtonian coefficients. We constrain the graviton Compton wavelength, assuming that gravitons are dispersed in vacuum in the same way as particles with mass, obtaining a 90%-confidence lower bound of 10^{13} km. In conclusion, within our statistical uncertainties, we find no evidence for violations of general relativity in the genuinely strong-field regime of gravity.

Massive black hole binaries from runaway collisions: the impact of metallicity

The runaway collision scenario is one of the most promising mechanisms to explain the formation of intermediate-mass black holes (IMBHs) in young dense star clusters. On the other hand, the massive stars that participate in the runaway collisions lose mass by stellar winds. In this paper, we discuss new N-body simulations of massive (6.5x10^4 Msun) star clusters, in which we added upgraded recipes for stellar winds and supernova explosion at different metallicity. We follow the evolution of the principal collision product (PCP), through dynamics and stellar evolution, till it forms a stellar remnant. At solar metallicity, the mass of the final merger product spans from few solar masses up to ~30 Msun. At low metallicity (0.01-0.1 Zsun) the maximum remnant mass is ~250 Msun, in the range of IMBHs. A large fraction (~0.6) of the PCPs are not ejected from the parent star cluster and acquire stellar or black hole (BH) companions. Most of the long-lived binaries hosting a PCP are BH-BH binaries. We discuss the importance of this result for gravitational wave detection.

CORE-COLLAPSE SUPERNOVAE FROM 9 TO 120 SOLAR MASSES BASED ON NEUTRINO-POWERED EXPLOSIONS

ABSTRACT Nucleosynthesis, light curves, explosion energies, and remnant masses are calculated for a grid of supernovae (SNe) resulting from massive stars with solar metallicity and masses from 9.0 to 120 M ⊙ . The full evolution is followed using an adaptive reaction network of up to 2000 nuclei. A novel aspect of the survey is the use of a one-dimensional neutrino transport model for the explosion. This explosion model has been calibrated to give the observed energy for SN 1987A, using five standard progenitors, and for the Crab SN using a 9.6 M ⊙ progenitor. As a result of using a calibrated central engine, the final kinetic energy of the SN is variable and sensitive to the structure of each pre-SN star. Many progenitors with extended core structures do not explode, but become black holes (BHs), and the masses of exploding stars do not form a simply connected set. The resulting nucleosynthesis agrees reasonably well with the Sun provided that a reasonable contribution from SNe Ia is also allowed, but with a deficiency of light s-process isotopes. The resulting neutron star initial mass function has a mean gravitational mass near 1.4 M ⊙ . The average BH mass is about 9 M ⊙ if only the helium core implodes, and 14 M ⊙ if the entire pre-SN star collapses. Only ∼10% of SNe come from stars over 20 M ⊙ , and some of these are Type Ib or Ic. Some useful systematics of Type IIp light curves are explored.

Stellar density profile and mass of the Milky Way bulge from VVV data

We present the first stellar density profile of the Milky Way bulge reaching latitude $b=0^\circ$. It is derived by counting red clump stars within the colour\--magnitude diagram constructed with the new PSF-fitting photometry from VISTA Variables in the V\'\i a L\'actea (VVV) survey data. The new stellar density map covers the area between $|l|\leq 10^\circ$ and $|b|\leq 4.5^\circ$ with unprecedented accuracy, allowing to establish a direct link between the stellar kinematics from the Giraffe Inner Bulge Spectroscopic Survey (GIBS) and the stellar mass density distribution. In particular, the location of the central velocity dispersion peak from GIBS matches a high overdensity in the VVV star count map. By scaling the total luminosity function (LF) obtained from all VVV fields to the LF from Zoccali et al.(2003), we obtain the first fully empirical estimate of the mass in stars and remnants of the Galactic bulge. The Milky Way bulge stellar mass within ($|b|<9.5^\circ$, $|l|<10^\circ$) is $2.0\pm0.3\times 10^{10}M_{\odot}$.

Thermodynamics of Black Holes and the Symmetric Generalized Uncertainty Principle

In this paper, we have investigated the thermodynamics of Schwarzschild black holes using the symmetric generalized uncertainty principle which contains correction terms involving momentum and position uncertainty. We obtain the mass-temperature relation and the heat capacity of the black hole using which we compute the critical and remnant masses. The entropy is found to satisfy the area law upto leading order corrections from the symmetric generalized uncertainty principle.

Indications and outcomes for Draf IIB frontal sinus surgery.

Extended frontal surgery techniques are often required when maximal medical therapy and standard endoscopic surgical approaches fail in patients. Although outcomes of the Draf III (modified Lothrop) procedure have been widely reported, postoperative outcomes and indications for the Draf IIB frontal sinusotomy have been relatively underreported. We presented our institution's experience with the Draf IIB procedure. Patients who underwent the Draf IIB frontal sinusotomy between 2007 and 2012 were identified by retrospective chart review. Data collected included demographics, imaging, sinus patency, and Sino-nasal Outcome Test 20 scores. A total of 22 Draf IIB frontal sinusotomies were performed in 18 patients. Thirteen of eighteen patients had previous frontal sinus surgery. The most common indications for the extended approach were chronic frontal sinusitis due to lateralized middle turbinate remnant (8 patients), mucocele (6), postoperative synechiae (5), and frontal sinus mass (3). Sinus ostium patency was maintained in 20 of 22 sinuses over an average follow-up period of 16.2 months. No complications were reported. The Draf IIB frontal sinusotomy is a relatively safe procedure, with multiple indications. Long-term sinus ostium patency was maintained in >90% of operated sinuses, which indicated that the Draf IIB procedure may present an acceptable alternative to more aggressive extended frontal sinus approaches in selected patients.

Extra-Abdominal Desmoid Tumor in the Donor Site of an Extended Latissimus Dorsi Flap.

Extra-Abdominal Desmoid Tumor in the Donor Site of an Extended Latissimus Dorsi Flap.

A Parametric Study on Free Vibration of Multi-perforated Rectangular Plates

This work involves study of the first three natural frequencies of the perforated plates. The effect of the parameters which influence them have been studied. The parameters considered are the shape of perforations, pattern of the perforations, aspect ratio of the plate, dimensions of the plate, ligament efficiency and the mass remnant ratio (MRR). The study is focused on the effect of the most influencing parameter on the free vibrations.

Baryon-number conservation in Bose-Einstein condensate black holes

Primordial black holes are studied in the Bose-Einstein condensate description of space-time. The question of baryon-number conservation is investigated with emphasis on possible formation of bound states of the system's remaining captured baryons. This leads to distinct predictions for both the formation time, which for the naively natural assumptions is shown to lie between $10^{-12}\.\srm$ to $10^{12}\.\srm$ after Big Bang, as well as for the remnant's mass, yielding approximately $3 \cdot 10^{23}\.{\rm kg}$ in the same scheme. The consequences for astrophysically formed black holes are also considered.

Classical and quantum Reissner-Nordström black hole thermodynamics and first order phase transition

First we consider CRNBH metric which is obtained by solving Einstein-Maxwell metric equation for a point electric charge $e$ inside of a spherical static body with mass $M$. It has 2 interior and exterior horizons. Using Bekenestein-Hawking entropy theorem we calculate interior and exterior entropy, temperature, Gibbs free energy and heat capacity at constant electric charge. We calculate first derivative of the Gibbs free energy with respect to temperature which become a singular function having a singularity at critical point with corresponding temperature $T_c=\frac{1}{24\pi \sqrt{3}|e|}.$ Hence we clime first order phase transition is happened there. Temperature same as Gibbs free energy takes absolutely positive (negative) values on the exterior (interior) horizon. The Gibbs free energy takes two different positive values synchronously for $0<T<T_c$ but not for negative values which means the system is made from two subsystem. For negative temperatures entropy reaches to zero value at $T\to-\infty$ and so takes Bose-Einstein condensation single state. Entropy increases monotonically in case $0<T<T_c$. Regarding results of the work presented at Ref. \citep{Bob01} we calculate again the mentioned thermodynamical variables for remnant stable final state of evaporating QRNBH and obtained results same as one in case of the CRNBH. Finally, we solve mass loss equation of QRNBH against advance Eddington-Finkelstein time coordinate and derive luminosity function. We obtain switching off of QRNBH evaporation before than the mass completely vanishes. It reaches to a could Lukewarm type of RN black hole which its final remnant mass is $m_{final}=|e|$ in geometrical units. Its temperature and luminosity vanish but not in Schwarzschild case of evaporation. Our calculations can be takes some acceptable statements about information loss paradox .