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Neutron stars provide a window into the properties of dense nuclear matter. Several recent observational and theoretical developments provide powerful constraints on their structure and internal composition. Among these are the first observed binary neutron star merger, GW170817, whose gravitational radiation was accompanied by electromagnetic radiation from a short γ-ray burst and an optical afterglow believed to be due to the radioactive decay of newly minted heavy r-process nuclei. These observations give important constraints on the radii of typical neutron stars and on the upper limit to the neutron star maximum mass and complement recent pulsar observations that established a lower limit. Pulse-profile observations by the Neutron Star Interior Composition Explorer (NICER) X-ray telescope provide an independent, consistent measure of the neutron star radius. Theoretical many-body studies of neutron matter reinforce these estimates of neutron star radii. Studies using parameterized dense matter equations of state (EOSs) reveal several EOS-independent relations connecting global neutron star properties.

Background Commercial horse feeds utilise cereal grains and byproducts; however, their effects on the caecal environment remain poorly characterised. Objective Characterise the effect of commonly used feed ingredients on caecal pH and volatile fatty acid (VFA) concentration. Study design 6 × 6 Latin square. Methods Two days prior to the start of the study, 6 caecally cannulated Quarter horses were moved into individual stalls where Smooth bromegrass hay (brome) was offered at 2.0% BW/d split between 2 feedings (0600 and 1800). On day 0, caecal digesta was collected every 2 h for 12 h relative to the 0600 feeding to establish control values for horses consuming only brome (HAY). On day 1, horses began consuming their respective treatments which consisted of beet pulp (BP), maize (M), dehydrated alfalfa (A), oats (OAT), soybean hulls (SBH), or wheat middlings (WM) at 0.25% BW/d split into 2 feedings. On day 7 of each treatment period, caecal digesta was collected every 2 h for 12 h and analysed for pH and VFA. Data were analysed using mixed ANOVA with repeated measures, fixed effects of treatment and time, and random effects of horse and period. Results There was a main effect of hour (P ≤ 0.05) indicative of post-prandial shifts in caecal metabolites. There were no main effects of treatment on pH or VFA concentration (P ≥ 0.3). Effects of hour × treatment (P ≤ 0.04) were observed for all response variables. Regardless of treatment or hour, caecal pH remained well within normal limits. Three horses exhibited signs of lower oesophageal choke immediately after consumption of BP pellets. Limitations Interactions between ingredients when mixed for formulation of a concentrate warrant further research. Furthermore, a short adaptation period was chosen to mimic common management practices. Conclusion Minimal differences in caecal fermentation parameters were detected when ingredients were fed at a common inclusion level.

A total of 72 male Boer goat kids (21.7 ± 0.5 kg) were fed for 21 d with 3 kids per pen and 12 pens per treatment. Dietary treatments were: 0% inclusion of dried distillers grains with solubles (DDGS; 0% DDGS) or 33% DDGS inclusion (33% DDGS) and were provided ad libitum. Goats and feeders were weighed weekly to collect body weights (BW) and determine feed disappearance in order to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). At the conclusion of the feeding study, a subset (n = 30; 2–3 goats from each pen representing six6 pens per treatment) of goats were harvested, carcasses evaluated, and loins were fabricated into 2.54 cm chops. Goat chop discoloration was evaluated by trained panelists and measured for L*, a*, and b* values on days 0, 4, 7, and 10 under retail display conditions. Samples were collected and analyzed for lipid oxidation, fatty acid profile, and hydrophilic and lipophilic antioxidant capacity. No evidence of differences was observed for final BW, ADFI, G:F, and carcass characteristics (P > 0.05). However, goats fed the 0% DDGS diet had greater ADG compared with those fed a diet containing 33% DDGS (P = 0.05). Overall, visual evaluation of discoloration, L*, a*, and b* as well as lipid oxidation data confirmed that feeding 33% DDGS to goats had no effect on goat chop discoloration and lipid oxidation (P > 0.10). However, all chops demonstrated a display effect, which they increased in visual discoloration and lipid oxidation and decreased in a* and b* values (P < 0.01) over the entirety of the 10-d period of retail display, regardless of the dietary treatments. As expected, feeding 33% DDGS to goats decreased relative percentage of multiple and total monounsaturated fatty acids, but increased relative percentage of multiple and total polyunsaturated fatty acids (PUFA; P < 0.05). The antioxidant capacity measurements showed no treatment difference in the hydrophilic portion (P > 0.10), but chops from the 33% DDGS treatment had greater lipophilic antioxidant activity compared with the 0% DDGS chops (P < 0.05). In conclusion, including 33% DDGS to the diet may negatively impact goat growth performance, but did not impact any carcass characteristics. Feeding a diet with 33% DDGS resulted in an increase in the PUFA content of goat chops but did not appear to impact meat color or lipid oxidation. The supposed negative consequence from increased PUFA is likely counterbalanced by the increased antioxidant capacity in the lipid component of meat, resulting in no difference in meat shelf-life.

Effects of Co on fiber digestibility in horses are largely unknown. Our objective was to evaluate effects of Co chloride on in vitro gas production, VFA production, and dry matter (DM) disappearance (IVDMD) using cecal fluid from 4 cannulated Quarter Horses. Five grams DM of alfalfa or smooth bromegrass hay were provided as substrate with Co added at 0.0, 0.5, 5.0, 25.0, or 50.0 mg/kg substrate DM. Ten milliliters cecal fluid and 140 mL McDougall's buffer were incubated in duplicate, and pH, VFA concentrations, and IVDMD were measured after 48 hours. Gas production, used as an indicator of fermentative activity, was recorded every 15 minutes. Terminal pH was not affected by Co or forage type (P.19). There was greater IVDMD in cultures containing alfalfa (29.2%) compared with smooth bromegrass hay (19.4%; P.01). There was a forage × Co interaction (P.05) in which gas production was greater in cultures containing alfalfa, and 5 mg Co/kg substrate DM led to greater gas production than 50 mg Co/kg substrate DM in cultures containing brome (P.05). Gas production was affected by forage, Co, and time (P.01). Production of individual and total VFA, as well as acetate:propionate (A:P) ratio were increased in cultures containing alfalfa (P.05); however, there were no effects of Co on VFA concentrations (P.05). While gas production was influenced by Co in cultures containing brome, no effects of Co were observed for pH, VFA, or IVDMD.

PSR J0740$+$6620 has a gravitational mass of $2.08\pm 0.07~M_\odot$, which is the highest reliably determined mass of any neutron star. As a result, a measurement of its radius will provide unique insight into the properties of neutron star core matter at high densities. Here we report a radius measurement based on fits of rotating hot spot patterns to Neutron Star Interior Composition Explorer (NICER) and X-ray Multi-Mirror (XMM-Newton) X-ray observations. We find that the equatorial circumferential radius of PSR J0740$+$6620 is $13.7^{+2.6}_{-1.5}$ km (68%). We apply our measurement, combined with the previous NICER mass and radius measurement of PSR J0030$+$0451, the masses of two other $\sim 2~M_\odot$ pulsars, and the tidal deformability constraints from two gravitational wave events, to three different frameworks for equation of state modeling, and find consistent results at $\sim 1.5-3$ times nuclear saturation density. For a given framework, when all measurements are included the radius of a $1.4~M_\odot$ neutron star is known to $\pm 4$% (68% credibility) and the radius of a $2.08~M_\odot$ neutron star is known to $\pm 5$%. The full radius range that spans the $\pm 1\sigma$ credible intervals of all the radius estimates in the three frameworks is $12.45\pm 0.65$ km for a $1.4~M_\odot$ neutron star and $12.35\pm 0.75$ km for a $2.08~M_\odot$ neutron star., Comment: 49 pages, 16 figures, submitted to The Astrophysical Journal Letters

We combine equation of state of dense matter up to twice nuclear saturation density ($n_{\rm sat}=0.16\, \text{fm}^{-3}$) obtained using chiral effective field theory ($��$EFT), and recent observations of neutron stars to gain insights about the high-density matter encountered in their cores. A key element in our study is the recent Bayesian analysis of correlated EFT truncation errors based on order-by-order calculations up to next-to-next-to-next-to-leading order in the $��$EFT expansion. We refine the bounds on the maximum mass imposed by causality at high densities, and provide stringent limits on the maximum and minimum radii of $\sim1.4\,{\rm M}_{\odot}$ and $\sim2.0\,{\rm M}_{\odot}$ stars. Including $��$EFT predictions from $n_{\rm sat}$ to $2\,n_{\rm sat}$ reduces the permitted ranges of the radius of a $1.4\,{\rm M}_{\odot}$ star, $R_{1.4}$, by $\sim3.5\, \text{km}$. If observations indicate $R_{1.4}1/2$ for densities above $2\,n_{\rm sat}$, or that $��$EFT breaks down below $2\,n_{\rm sat}$. We also comment on the nature of the secondary compact object in GW190814 with mass $\simeq 2.6\,{\rm M}_{\odot}$, and discuss the implications of massive neutron stars $>2.1 \,{\rm M}_{\odot}\,(2.6\,{\rm M}_{\odot})$ in future radio and gravitational-wave searches. Some form of strongly interacting matter with $c^2_{s}>0.35\, (0.55)$ must be realized in the cores of such massive neutron stars. In the absence of phase transitions below $2\,n_{\rm sat}$, the small tidal deformability inferred from GW170817 lends support for the relatively small pressure predicted by $��$EFT for the baryon density $n_{\rm B}$ in the range $1-2\,n_{\rm sat}$. Together they imply that the rapid stiffening required to support a high maximum mass should occur only when $n_{\rm B} \gtrsim 1.5-1.8\,n_{\rm sat}$., 26 pages, 17 figures; accepted for publication in PRC, appendices and references updated

Enogen Feed Corn (EFC; Syngenta Seeds, LLC, Downers Grove, IL) hybrids contain a trait for expression of heat-stable α-amylase in the grain. α-Amylase is an enzyme responsible for breakdown of starch in the small intestine; supplementation of exogenous α-amylase to pigs may result in greater starch digestibility and thus improved gain efficiency. A total of 288 pigs (Line 600 × 241, DNA, Columbus, NE; initially 41.6 kg) were utilized in an 82-d trial to determine if replacing conventional yellow dent corn (CONV) with EFC in diets with or without distillers dried grains with solubles (DDGS) influences growth performance and carcass characteristics. Pens of pigs were randomly assigned to one of four dietary treatments balancing for initial body weight. There were nine pens per treatment with eight pigs per pen (an equal number of barrows and gilts per pen). Treatments were arranged in a 2 × 2 factorial with main effects of corn source (CONV or EFC) and DDGS (0% or 25%). Experimental diets were fed in meal form in three phases: days 0 to 29, 29 to 47, and 47 to 82. Pigs were weighed approximately every 2 wk and at the beginning of each phase. On day 82, pigs were transported to a commercial abattoir for processing and carcass data collection. Data were analyzed using PROC GLIMMIX procedure of SAS with pen as the experimental unit. There were no corn source by DDGS interactions (P > 0.05) observed for overall performance or carcass characteristics. Overall, average daily gain (ADG) was marginally greater (P < 0.089) for pigs fed EFC than CONV with no evidence (P > 0.196) for difference in average daily feed intake (ADFI), gain:feed ratio (G:F), hot carcass weight (HCW), or other carcass traits. Addition of DDGS decreased (P < 0.047) overall ADG and G:F. Pigs fed DDGS had marginally lower (P < 0.071) HCW, less (P < 0.050) backfat depth, greater (P < 0.026) loin depth, and greater (P < 0.020) percentage lean and carcass fat iodine value (IV). In summary, addition of 25% DDGS to the diet decreased ADG and increased carcass fat IV. Pigs fed EFC tended to have improved overall ADG; however, G:F and carcass characteristics were not different between corn sources. These results suggest that EFC, although not beneficial, may be used as a substitute for CONV without any deleterious effects on growth performance. Further research should be conducted to understand whether addition of EFC to swine diets could be beneficial in younger pigs exhibiting decreased pancreatic α-amylase secretion following weaning or whether heat treatment of diets, such as pelleting, may influence the response to EFC.

We report on Bayesian estimation of the radius, mass, and hot surface regions of the massive millisecond pulsar PSR J0740$+$6620, conditional on pulse-profile modeling of Neutron Star Interior Composition Explorer X-ray Timing Instrument (NICER XTI) event data. We condition on informative pulsar mass, distance, and orbital inclination priors derived from the joint NANOGrav and CHIME/Pulsar wideband radio timing measurements of arXiv:2104.00880. We use XMM European Photon Imaging Camera spectroscopic event data to inform our X-ray likelihood function. The prior support of the pulsar radius is truncated at 16 km to ensure coverage of current dense matter models. We assume conservative priors on instrument calibration uncertainty. We constrain the equatorial radius and mass of PSR J0740$+$6620 to be $12.39_{-0.98}^{+1.30}$ km and $2.072_{-0.066}^{+0.067}$ M$_{\odot}$ respectively, each reported as the posterior credible interval bounded by the 16% and 84% quantiles, conditional on surface hot regions that are non-overlapping spherical caps of fully-ionized hydrogen atmosphere with uniform effective temperature; a posteriori, the temperature is $\log_{10}(T$ [K]$)=5.99_{-0.06}^{+0.05}$ for each hot region. All software for the X-ray modeling framework is open-source and all data, model, and sample information is publicly available, including analysis notebooks and model modules in the Python language. Our marginal likelihood function of mass and equatorial radius is proportional to the marginal joint posterior density of those parameters (within the prior support) and can thus be computed from the posterior samples., Comment: 40 pages, 16 figures (3 of which are figure sets), 1 animation, 2 tables. ApJL accepted version. Software: https://github.com/ThomasEdwardRiley/xpsi. Zenodo: https://doi.org/10.5281/zenodo.4697624. (v1 = submitted version; v2 = accepted version; v3 = metadata edits)

In recent years our understanding of the dense matter equation of state (EOS) of neutron stars has significantly improved by analyzing multimessenger data from radio/X-ray pulsars, gravitational wave events, and from nuclear physics constraints. Here we study the additional impact on the EOS from the jointly estimated mass and radius of PSR J0740+6620, presented in Riley et al. (2021) by analyzing a combined dataset from X-ray telescopes NICER and XMM-Newton. We employ two different high-density EOS parameterizations: a piecewise-polytropic (PP) model and a model based on the speed of sound in a neutron star (CS). At nuclear densities these are connected to microscopic calculations of neutron matter based on chiral effective field theory interactions. In addition to the new NICER data for this heavy neutron star, we separately study constraints from the radio timing mass measurement of PSR J0740+6620, the gravitational wave events of binary neutron stars GW190425 and GW170817, and for the latter the associated kilonova AT2017gfo. By combining all these, and the NICER mass-radius estimate of PSR J0030+0451 we find the radius of a 1.4 solar mass neutron star to be constrained to the 95% credible ranges 12.33^{+0.76}_{-0.81} km (PP model) and 12.18^{+0.56}_{-0.79} km (CS model). In addition, we explore different chiral effective field theory calculations and show that the new NICER results provide tight constraints for the pressure of neutron star matter at around twice saturation density, which shows the power of these observations to constrain dense matter interactions at intermediate densities., 17 pages, 8 figures; accepted for publication in the Astrophysical Journal Letters

An experiment was conducted with 6 cecally cannulated horses (524 ± 65.5 kg BW) to evaluate effects of increasing dietary starch on equine cecal microbiota. Starch was supplied via corn pellets and was increased by 0.5 g starch/kg BW/meal every 7 d until horses received 3.5 g starch/kg BW/meal. Throughout the experiment, Smooth Bromegrass hay and water were offered ad libitum. Meals were fed every 6 h, starting at 0600 h. On d 7 of each period, cecal digesta was collected every 2 h for 12 h. Within period, cecal samples for each horse were pooled and DNA was extracted for PCR amplification of the 16 S rRNA gene (V3 and V4 regions) and sequencing via Illumina MiSeq. Alpha and beta diversity were measured. Data were analyzed as a randomized complete block with fixed effect of starch level and random effect of horse (SAS version 9.4). If a horse presented with colic, it was removed from the experiment. Parameters when feeding 1.5 g starch/kg BW/meal were compared between horses which completed the trial and those removed using covariate of 0 g starch/kg BW/meal. Feeding 1.5 g starch/kg BW/meal elicited the greatest changes in microbiota, indicated by reduced (P ≤ 0.02) operational taxonomical units and Faith phylogenetic diversity and different (P ≤ 0.017) beta diversity compared to all other treatments. Across treatments, Firmicutes was the most abundant phyla, followed by Bacteroidetes. Feeding 1.5 g starch/kg BW/meal led to lowest (P ≤ 0.0342) relative abundance (RA) of Prevotella, Treponema, Phascolarctobacterium, and [Prevotella]. Horses that persisted throughout the experiment had reduced (P = 0.0163) RA of Ruminococcus and greater RA of Phascolarctobacterium (P = 0.0057) when consuming 1.5 g starch/kg BW/meal compared to those removed. This is the first report describing effects of gradually increasing dietary starch on equine cecal microbiota in vivo.

The objective of this study was to evaluate the efficacy of corn dried distillers grains with solubles (DDGS) or corn gluten feed (CGF) as a replacement for soybean meal (SBM) in a Boer goat diet. A total of 75 meat goat kids (26.9 0.2 kg) were placed in 25 pens (3 kids per pen and 5 pens per treatment) for a 35-day experimental period at the Kansas State University Sheep and Meat Goat Center. Kids were allotted to one of the following isocaloric and isonitrogenous diets that varied in protein source: 1) SBM; 2) 100% DDGS/0% CGF; 3) 66% DDGS/33% CGF; 4) 33% DDGS/66% CGF; and 5) 0% DDGS/100% CGF. Diets were pelleted and supplied the sole source of nutrition. Goats and feeders were weighed weekly to determine ADG, ADFI, G:F, cost per kg of diet, and cost per kg of gain. Data were analyzed using the GLIMMIX procedure of SAS (SAS Inst., Cary, NC) with pen serving as the experimental unit. Differences were considered significant if P0.05. Treatment did not impact BW (P = 0.999), ADG (P = 0.723), ADFI (P = 0.210), or G:F (P = 0.796; Table 2). While diet cost differed due to differences in price of soybean meal and the corn co-products, there was no evidence (P = 0.941) that cost per kg of gain was less for goats fed the corn co-products. However, feed cost per goat was less (P = 0.0008) with diets containing corn co-products, regardless of level. These data allow producers to make more informed feeding decisions with a broader understanding of potential implications of corn gluten feed use in goats.

Students enter graduate school with a primary species of interest and may have little to no desire for comparative and collaborative work. Indeed, intent focus on a single species is critical to their development as subject matter experts. But, working collaboratively with other graduate students and faculty in a secondary or tertiary species can be immensely beneficial to their education and growth. Upon graduation, whether in academia or industry, young professionals must collaborate with their colleagues in order to be successful. Commonly, this means working with others who are not directly involved in their area of focus. Developing these skill sets in graduate school promotes a more well-rounded applicant. Additionally, upon graduation, students may find their “perfect” position is not available. Working across multiple species affords them the opportunity to apply to a multitude of jobs that would otherwise be unavailable in a single species program.

A total of 288 pigs (Line 600 241, DNA, Columbus, NE; initially 41.6 kg) were used in an 82-d trial to determine if replacing conventional yellow dent corn with high amylase corn (Enogen®, Syngenta Seeds, LLC, Downers Grove, IL) in diets with or without distillers dried grains with solubles (DDGS) influences growth performance and carcass characteristics. Diets were arranged in a 2 × 2 factorial with 2 corn sources (yellow dent or high amylase) and 2 levels of DDGS (0 or 25%). Experimental diets were fed in meal form in 3 phases: d 0 to 29, 29 to 47, and 47 to 82. There were 9 pens/treatment each containing an equal number of barrows and gilts. Pigs were weighed approximately every 2 wk and at the beginning of each phase. On d 82, pigs were transported to a commercial packing plant for processing and carcass data collection. Data were analyzed using PROC GLIMMIX procedure of SAS with pen as the experimental unit. There were no interactions (P > 0.05) between corn source and DDGS inclusion for overall performance or carcass characteristics. Overall, average daily gain (ADG) was marginally greater (P < 0.089) for pigs fed high amylase than yellow dent corn with no evidence (P > 0.196) for difference in feed intake, feed efficiency (G/F), hot carcass weight (HCW), or other carcass traits. Addition of DDGS resulted in decreased (P < 0.037) overall ADG and G/F. Pigs fed DDGS had marginally lower (P < 0.071) HCW, less (P < 0.050) backfat, greater (P < 0.026) loin depth, and greater (P < 0.020) percentage lean and iodine values. In summary, high amylase corn tended to improve overall ADG; however, feed efficiency and carcass characteristics were unchanged between corn sources. Consistent with previous research, addition of DDGS decreased ADG and increased IV.

We explore constraints on the equation of state (EOS) of neutron-rich matter based on microscopic calculations up to nuclear densities and observations of neutron stars. In a previous work we showed that predictions based on modern nuclear interactions derived within chiral effective field theory and the observation of two-solar-mass neutron stars result in a robust uncertainty range for neutron star radii and the EOS over a wide range of densities. In this work we extend this study, employing both the piecewise polytrope extension from Hebeler et al. as well as the speed of sound model of Greif et al., and show that moment of inertia measurements of neutron stars can significantly improve the constraints on the EOS and neutron star radii., 11 pages, 10 figures, published version

The effect of hay type on the microbiome of the equine gastrointestinal tract is relatively unexplored. Our objective was to characterize the cecal and fecal microbiome of mature horses consuming alfalfa or Smooth Bromegrass (brome) hay. Six cecally cannulated horses were used in a split-plot design run as a crossover in two periods. The whole plot treatment was ad libitum access to brome or alfalfa hay fed over two 21-d acclimation periods with subplots of sampling location (cecum and rectum) and sampling hour. Each acclimation period was followed by a 24-h collection period where cecal and fecal samples were collected every 3 h for analysis of pH and volatile fatty acids (VFA). Fecal and cecal samples were pooled and sent to a commercial lab (MR DNA, Shallowater, TX) for the amplification of the V4 region of the 16S rRNA gene and sequenced using Illumina HiSeq. The main effects of hay on VFA, pH, and taxonomic abundances were analyzed using the MIXED procedure of SAS 9.4 with fixed effects of hay, hour, location, period, and all possible interactions and random effect of horse. Alpha and beta diversities were analyzed using the R Dame package. Horses fed alfalfa had greater fecal than cecal pH (P ≤ 0.05), whereas horses fed brome had greater cecal than fecal pH (P ≤ 0.05). Regardless of hay type, total VFA concentrations were greater (P ≤ 0.05) in the cecum than in feces, and alfalfa resulted in greater (P ≤ 0.05) VFA concentrations than brome in both sampling locations. Alpha diversity was greater (P ≤ 0.05) in fecal compared with cecal samples. Microbial community structure within each sampling location and hay type differed from one another (P ≤ 0.05). Bacteroidetes were greater (P ≤ 0.05) in the cecum compared with the rectum, regardless of hay type. Firmicutes and Firmicutes:Bacteroidetes were greater (P ≤ 0.05) in the feces compared with cecal samples of alfalfa-fed horses. In all, fermentation parameters and bacterial abundances were impacted by hay type and sampling location in the hindgut.

The possible detection of a compact object in the remnant of SN 1987A presents an unprecedented opportunity to follow its early evolution. The suspected detection stems from an excess of infrared emission from a dust blob near the compact object's predicted position. The infrared excess could be due to the decay of isotopes like 44Ti, accretion luminosity from a neutron star or black hole, magnetospheric emission or a wind originating from the spindown of a pulsar, or thermal emission from an embedded, cooling neutron star (NS 1987A). It is shown that the last possibility is the most plausible as the other explanations are disfavored by other observations and/or require fine-tuning of parameters. Not only are there indications the dust blob overlaps the predicted location of a kicked compact remnant, but its excess luminosity also matches the expected thermal power of a 30 year old neutron star. Furthermore, models of cooling neutron stars within the Minimal Cooling paradigm readily fit both NS 1987A and Cas A, the next-youngest known neutron star. If correct, a long heat transport timescale in the crust and a large effective stellar temperature are favored, implying relatively limited crustal n-1S0 superfluidity and an envelope with a thick layer of light elements, respectively. If the locations don't overlap, then pulsar spindown or accretion might be more likely, but the pulsar's period and magnetic field or the accretion rate must be rather finely tuned. In this case, NS 1987A may have enhanced cooling and/or a heavy-element envelope., Comment: 21 pages, 6 figures, to be published in ApJ

The NICER collaboration recently published a joint estimate of the mass and the radius of PSR J0030+0451, derived via X-ray pulse-profile modeling. Raaijmakers et al. (2019) explored the implications of this measurement for the dense matter equation of state (EOS) using two parameterizations of the high-density EOS: a piecewise-polytropic model, and a model based on the speed of sound in neutron stars. In this work we obtain further constraints on the EOS following this approach, but we also include information about the tidal deformability of neutron stars from the gravitational wave signal of the compact binary merger GW170817. We compare the constraints on the EOS to those set by the recent measurement of a 2.14 solar mass pulsar, included as a likelihood function approximated by a Gaussian, and find a small increase in information gain. To show the flexibility of our method, we also explore the possibility that GW170817 was a neutron star-black hole merger, which yields weaker constraints on the EOS., 18 pages, 8 figures. Accepted for publication in ApJ Letters

Eight cecally cannulated Quarter Horses were used in a replicated 4 × 4 Latin square experiment conducted in four 14-d periods to determine effects of sodium caseinate (casein) on hindgut fermentation and fiber digestion. During each period, horses were assigned to one of four treatments consisting of control (water; CON), 0.125 g casein/kg BW (LOW), 0.25 g casein/kg BW (MED), or 0.5 g casein/kg BW (HI). Casein was solubilized in 800 mL water and dosed directly into the cecum at 0700 and 1900 hours using a metal dosing syringe. Smooth Bromegrass hay (CP 8.50%), water, and salt were provided ad libitum. New hay was fed at 0700 and 1900 hours, and orts were recorded at 1900 daily. During the final 3 d of each period, cecal digesta were collected every 6 h, pH was measured, and samples were frozen for subsequent analyses of VFA and NH(3) concentrations. Feed intake during the final 4 d of each period was recorded. Feces were collected during the 3-d sampling period, pooled, subsampled, and frozen. Fecal samples were analyzed for pH and used to determine digestibilities of DM, OM, NDF, and ADF. Statistical analyses were performed via the GLIMMIX procedure of SAS 9.4. Linear and quadratic effects of sodium caseinate on pH, VFA concentrations, and apparent digestibility were assessed by SAS. Digestibilities of DM, OM, ADF, and NDF were unaffected by treatment (P > 0.40). Horses dosed with CON and MED treatments had greater cecal pH than those fed LOW or HI treatments (P < 0.01). Cecal NH(3) concentrations increased linearly in response to the amount of casein administered (P < 0.01). Cecal NH(3) decreased 6 h after dosing and addition of new hay, regardless of treatment (P < 0.01). Total cecal VFA were unaffected by treatment (P > 0.10), but VFA changed over time with the greatest concentrations observed 6 h after treatments were administered and introduction of new hay (P < 0.01). Treatment did not affect DMI (P ≥ 0.17). In this experiment, cecal infusions of sodium caseinate had minimal to no effect on fermentation parameters or fiber degradation in the horse. A type II error may have occurred due to small population size or the medium quality hay fed to these horses provided sufficient N for microbial fermentation.

Two experiments were conducted to evaluate corn dried distiller’s grains with solubles (DDGS) and corn gluten feed (CGF) as replacements for soybean meal (SBM) and determine the impact of an ionophore on Boer goat growth performance and carcass characteristics. In Exp. 1, 75 Boer-goat kids (initial BW 26.9 ± kg) were allotted to one of 5 dietary treatments: 1) Negative control (100% SBM, 0% DDGS and 0% CGF; 100SBM); 2) Positive control (100% DDGS, 0% CGF and 0% SBM; 100DDGS); 3) 66% DDGS, 33% CGF and 0% SBM (66DDGS/33CGF); 4) 66% CGF, 33% DDGS and 0% SBM (33DDGS/66 CGF); and 5) 100% CGF, 0% DDGS and 0% SBM (0DDGS/100CGF). Dietary treatment did not impact (P ≤ 0.21) growth. In Exp. 2, 72 Boer-goat kids (initial BW 21.7 ± kg) were allotted to one of 4 dietary treatments in a 2 X 2 factorial with 2 protein sources and 2 ionophore inclusions: 1) SBM/no ionophore (SBM-NI); Diet 2) SBM with ionophore (SBM-I); Diet 3) DDGS/no ionophore (DDGS-NI); and Diet 4) DDGS with ionophore (DDGS-I). On d 21, goats were split into 2 groups according to their protein source and fed an additional d 10 (Group 1: DDGS-I; Group 2: SBM-I). The 15 heaviest goats from each group were harvested and carcass data collected. The protein source X ionophore interaction was not significant (P ≥ 0.15) for any measured response criteria. Goats fed a diet with SBM had significantly increased (P = 0.04) ADG compared to goats fed DDGS. No evidence of difference was observed (P ³ 0.10) for ADFI or G:F. Dietary treatment did not impact (P > 0.05) carcass characteristics. In summary, these data suggest that corn co-products can be economically included in Boer-goat diets, however their impact on growth performance is variable compared to that of soybean meal.

Quark matter may appear due to a hadronic-quark transition in the core of a hybrid star. Quarkyonic matter is an approach in which both quarks and nucleons appear as quasi-particles in a crossover transition, and provides an explicit realization of early ideas concerning quark matter (e.g., the MIT bag model). This description has recently been employed by McLerran and Reddy to model chargeless (pure neutron) matter with an approach that has the virtue that the speed of sound rises quickly at a neutron-quark transition so as to satisfy observational constraints on the neutron star maximum mass ($\gtrsim2M_\odot$) and the radius of a $1.4M_\odot$ star ($R_{1.4}\lesssim 13.5$ km). Traditional models involving first-order transitions result in softer pressure-energy density relations that have difficulty satisfying these constraints except with very narrow choices of parameters. We propose a variation of quarkyonic matter involving protons and leptons whose energy can be explicitly minimized to achieve both chemical and beta equilibrium, which cannot be done in the chargeless formulation. Quarkyonic stellar models are able to satisfy observed mass and radius constraints with a wide range of model parameters, avoiding the obligatory fine-tuning of conventional hybrid star models, including requiring the transition density to be very close to the nuclear saturation density. Our formulation fits experimental and theoretical properties of the nuclear symmetry energy and pure neutron matter, and contains as few as three free parameters. This makes it an ideal tool for the study of high-density matter that is an efficient alternative to piecewise polytrope or spectral decomposition methods., Comment: 12 pages, 12 figures. Accepted by PRD. Add nud version of quarkyonic EoS in Appendix. Python code of nud version posted on https://github.com/sotzee/quaryonic_eos

Calcium salts of fatty acids (CSFAs) frequently are fed to ruminants, but their fate in the equine digestive system is unknown. The purpose of this study was to compare Enertia s/f, a proprietary CSFAs, and soybean (SB) oil with respect to impact on apparent total tract nutrient digestion and cecal fermentation parameters in horses. Eight cecally cannulated Quarter Horses were used in a crossover design in which horses consumed a diet for 32 d consisting of 1.5% body weight (BW) (as-fed) smooth bromegrass hay and 0.5% BW (as-fed) pelleted concentrate containing 4.9% CSFAs or 4.1% SB oil. Fecal samples were collected every 4 h from day 30 to 32 of each period and analyzed for apparent total tract digestibilities of dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein (CP), crude fat (CF), and gross energy (GE) using acid detergent insoluble ash as an internal marker. Cecal digesta was obtained at 0, 2, 4, 6, 8, 10, and 12 h following the morning meal on day 29 of each period and analyzed for pH and concentrations of volatile fatty acid (VFA) and long-chain fatty acids (LCFAs). Serum was collected on day 33 of each period following a 16-h fast and analyzed for triglycerides and cholesterol. Apparent total tract digestibilities of DM, NDF, ADF, CP, CF, and GE were unaffected by lipid source (P > 0.10). Serum triglycerides tended to be greater in horses consuming CSFAs compared to SB (P = 0.10); however, serum cholesterol was not different (P = 0.45). In horses consuming SB, cecal pH decreased below baseline (hour 0) at hours 2, 4, and 6 (P 0.10). Cecal concentrations of total VFAs were greater in horses consuming SB compared to CSFAs at hour 2 (P = 0.01). Cecal concentrations of acetate, propionate, acetate:propionate (A:P), and butyrate were affected by time (P

To assess the impact of protein on fermentation by equine cecal microorganisms, cecal fluid from 4 cecally cannulated horses was used to inoculate fermentation bottles containing buffer, forage, and supplemental protein. In experiment 1, sodium caseinate (SC) provided 0, 0.5%, 1%, 2%, or 4% additional crude protein (CP) to bottles containing alfalfa or native warm-season prairie grass hay. Bottles were equipped with continuous gas pressure monitors and placed into a shaking incubator for 48 hours at 39°C. Cultures with alfalfa had greater (P < .0001) in vitro dry matter disappearance (IVDMD), neutral detergent fiber disappearance (NDFD), acid detergent fiber disappearance (ADFD), cumulative gas production, and total volatile fatty acid (VFA). Sodium caseinate increased gas production (P ≤ .05) and decreased pH (P < .003) in cultures with grass hay. Sodium caseinate at 1%, 2%, or 4% additional CP increased IVDMD, NDFD, and ADFD (P < .01), while 4% additional CP also increased total VFA (P < .01). For experiment 2, SC, fishmeal, soybean meal (SBM), whey, porcine blood plasma, and L-lysine hydrochloride were added to supply 2% additional CP to cultures with grass hay. All protein sources decreased pH and increased IVDMD, NDFD, and ADFD (P ≤ .01), with the largest effects elicited by SC, L-lysine, and whey (P ≤ .05). Total VFA (P ≤ .04) and gas (P ≤ .05) production increased with L-lysine, whey, SC, SBM, and fishmeal. While protein supplementation had minimal effects on cultures containing alfalfa, it altered fermentation of grass hay, more notably with more soluble protein sources.

With a growing goat population in the United States comes a greater emphasis on understanding the role of inexpensive or alternative ingredients in goat diets. However limited data is available on how these ingredients impact goat carcass composition. The objective of this experiment was to evaluate the impact of protein or chloride source on Boer goat carcass characteristics. Growing goats were fed 1 of 5 isocaloric and isonitrogenous diets for 42 d prior to slaughter in a completely randomized design. Diets included the following as their protein and primary chloride source: 1) soybean meal (SBM) with ammonium chloride (AmCl); 2) dried distillers grains with solubles (DDGS) with AmCl; 3) SoyPlus (Dairy Nutrition Plus, Ames, IA) with AmCl; 4) SBM with SoyChlor (Dairy Nutrition Plus, Ames, IA); and 5) SoyPlus with SoyChlor. Fifty goats (10 per treatment) were slaughtered in a USDA-inspected facility (Paradise Locker Meats, Trimble, MO), with carcass data collected initially (HCW) or after a 24-h chill. Data were analyzed using the GLIMMIX procedure on SAS, with goat as the experimental unit. Differences in final body weight were not detected among dietary treatments (P = 0.284), nor were there differences in hot carcass weight or carcass yield (P > 0.05). Goats fed diets with SBM, regardless of chloride source, had greater (P < 0.05) loin eye area than those fed diets with SoyPlus and SoyChlor. There was no detected impact (P > 0.05) of dietary treatment on goat backfat depth or body wall thickness. In summary, the ingredients tested had limited impact on yield or fat proportion in goats when calorie and crude protein levels were held constant. However, goats fed SBM-based diets had greater loin eye area than those fed SoyPlus and SoyChlor.

Limited research for least cost goat diets is available for meat goat producers. The objective of this project was to evaluate the impact of protein source or chloride source on Boer goat growth performance. Because diets were isonitrogenous and isocaloric, it was hypothesized that the replacement of soybean meal (SBM) and ammonium choloride (AmCl) with alternative protein and Cl sources would reduce diet costs without impacting growth performance. To test this hypothesis, 75 Boer-influenced goats (23.5 ± 2.9 kg BW; approximately 75 d of age) were allocated to 5 treatments in a completely random design in a climate-controlled facility of the Kansas State University Sheep and Meat Goat Center. Goats were stratified by BW into 25 pens (5 pens/treatment; 3 goats/pen) for a 42 d finishing study. Diets included: 1) SBM with AmCl; 2) dried distillers grains with solubles (DDGS) with AmCl; 3) SoyPlus with AmCl; 4) SBM with SoyChlor; and 5) SoyPlus with SoyChlor. Data were analyzed using the GLIMMIX procedure of SAS with pen as the experimental unit. There were no detectable differences of dietary treatment on ADG, ADFI, or G:F (P > 0.05). Using a pre-planned contrast statement, it was revealed goats fed diets with AmCl had lower ADG than goats fed diets with SoyChlor (P = 0.013; 125 vs. 165 g/d, respectively). While growth performance was relatively similar, the ingredient costs varied, leading to differences in feed cost per goat (P < 0.0001; $19.60, $16.07, $18.03, $25.82, $23.14 for diets containing SBM with AmCl, DDGS with AmCl, SoyPlus with AmCl, SBM with SoyChlor, SoyPlus with SoyChlor, respectively). These results confirm the hypothesis that goats can have similar growth responses with lower feed costs, leaving producers with options for optimizing growth performance on a least cost basis.

Due to increased use of dried distillers grains with solubles (DDGS) in animal feed and accessibility of ethanol plants in the Midwest, the effect of feeding DDGS in place of soybean meal (SBM) on growth, economics, carcass characteristics, backfat fatty acid profiles, and fecal microbiome of Boer-cross goats was evaluated. Forty-eight Boer-cross goats (approximately 70 d of age; 28.21 ± 0.96 kg) were blocked by BW and assigned to 1 of 4 dietary treatments in a completely randomized design. Treatments were 0 %, 33 %, 66 %, or 100 % DDGS replacing SBM, equating to the inclusion of 0 % (0DDGS), 10.3 % (10DDGS), 20.5 % (20DDGS), or 31.1 % (30DDGS) DDGS in the total diet. The inclusion rates of corn and soybean hulls were adjusted to maintain isocaloric and isonitrogenous diets. Goats were provided ad libitum access to feed and water for 47 d. There were 3 goats/pen and 4 pens/treatment. The inclusion of DDGS linearly improved (P = 0.01) average daily gain (ADG) and gain:feed (G:F; P = 0.001), without affecting average daily feed intake (ADFI; P > 0.10) in goats fed DDGS in place of SBM. Feed cost/kg gain decreased (P

In vitro fermentation systems allow researchers to mimic the equine hindgut while providing quick, affordable, and publishable data. However, the substrate:buffer ratio within the system has a profound impact on subsequent fermentation parameters. The objective of this study was to evaluate effects of varying substrate levels on culture pH, gas production, dry matter disappearance (DMD), neutral detergent fiber disappearance (NDFD), and volatile fatty acid (VFA) concentrations utilizing the ANKOM RF Gas Production System (ANKOM Technology; Macedon, NY). Cecal fluid was collected from 4 cecally cannulated Quarter horses and used to inoculate fermentation bottles containing buffer and substrate. Substrate consisted of brome or corn included at 0.5, 1, 1.5, 2, 3, or 4 g/flask (dry matter basis) while buffer and inoculant remained constant at 125 and 25 mL/flask, respectively. Flasks were equipped with continuous gas pressure monitors and placed into a shaking incubator for 48 h at 39°C. Data were analyzed using mixed models with fixed effects of treatment, time, and treatment by time interaction, repeated effect of time, and random effects of run by horse within run. Changes in gas production, VFA production, and terminal pH were proportion to substrate amount for cultures containing 0.5 to 2 g of substrate, but were less for cultures with 3 or 4 g of substrate (linear and quadratic effects, P

Recent developments in the theory of pure neutron matter and experiments concerning the symmetry energy of nuclear matter, coupled with recent measurements of high-mass neutron stars, now allow for relatively tight constraints on the equation of state of dense matter. We review how these constraints are formulated and describe the implications they have for neutron stars and core-collapse supernovae. We also examine thermal properties of dense matter, which are important for supernovae and neutron star mergers, but which cannot be nearly as well constrained at this time by experiment. In addition, we consider the role of the equation of state in medium-energy heavy-ion collisions., Comment: 87 pages, 20 figures, Accepted for Phys. Rep (Gerald E. Brown's Memorial Volume)

The objective of this study was to evaluate the impact of liquid blueberry juice (BJ65) or blueberry puree (BP30) used as a binding agent on pellet durability and palatability of a typical equine concentrate when included at 4% of the pellet. Molasses was used as a control. Production data, pellet durability and moisture content were evaluated in 1 replicate for each treatment. Because moisture content of condition mashes were 17.59% and 18.11% for BJ65 and BP30 treatments, respectively, greater inclusion of blueberry product would likely cause roller slippage and complicate the pelleting process due to increased liquid (Fahrenholz, 2012). Pellet durability met industry standards for all treatments. Pellets were fed in a 3 x 3 Latin square design to 9 two-year-old horses to determine the effect of blueberry products on acceptability. All animals were allowed 10 minutes to consume 1.36 kg at 0700 h and 1700 h each day for 3 d. Consumption time and amount consumed were recorded to calculate intake, intake rate, and intake ratio (IR). No horse consumed all pellets within the allotted time, and thus, there were no differences between intake rate and intake. Period tended to impact intake (P = 0.0909), with horses consuming less during period 1 than period 3 (P = 0.0317), but period had no effect (P = 0.2881) on IR. Treatment influenced intake (P < 0.0001), with decreased intake of BP30 compared to control and BJ65 (P ≤ 0.0001). Intake ratio was greater (P = 0.0075) for BJ65 than BP30 with IR of 0.5069 and 0.4227, respectively. Consumption of BJ65 was no different than control. Fahrenholz, A. 2012. Evaluating factors affecting pellet durability and energy consumption in a pilot feed mill and comparing methods for evaluating pellet durability. Doctoral thesis. Kansas State University, Manhattan, KS.

We present a study of how a low-temperature accreted atmosphere influences the emitted X-ray spectrum of a neutron star. The atmosphere models and spectra were computed with Zcode, a multigroup radiation transfer code developed at the Los Alamos National Laboratory. Though the underlying hot neutron star behaves as a blackbody, the atmosphere shifts the peak of spectrum away from a blackbody and toward higher energies, producing an emitted spectrum similar to a dilute blackbody. Quantifying the effects of this atmosphere will remove a source of uncertainty in X-ray observations and better constrain the mass-radius relation for neutron stars and thus the equation of state of dense matter. We present a suite of these atmospheres with varying compositions and temperatures as well as the resulting spectra.

This contribution describes constraints on neutron star masses and radii, and the underlying dense matter equation of state, from general relativity, causality, and the observed lower limit to the neutron star maximum mass. Further constraints can be achieved from theoretical studies of neutron matter, including a lower bound on its energy from the unitary gas, and experimental studies of nuclei. These constraints are compared to observational X-ray measurements of photospheric radius expansion bursts and quiescent low-mass binaries. The recent observation of gravitational waves from the binary neutron star merger GW170817 has provided even more powerful constraints. Upcoming measurements from phase-resolved spectroscopy of pulsars and the moment of inertia of PSR J0737-3039A are also discussed.This contribution describes constraints on neutron star masses and radii, and the underlying dense matter equation of state, from general relativity, causality, and the observed lower limit to the neutron star maximum mass. Further constraints can be achieved from theoretical studies of neutron matter, including a lower bound on its energy from the unitary gas, and experimental studies of nuclei. These constraints are compared to observational X-ray measurements of photospheric radius expansion bursts and quiescent low-mass binaries. The recent observation of gravitational waves from the binary neutron star merger GW170817 has provided even more powerful constraints. Upcoming measurements from phase-resolved spectroscopy of pulsars and the moment of inertia of PSR J0737-3039A are also discussed.

We report on Bayesian parameter estimation of the mass and equatorial radius of the millisecond pulsar PSR J0030$+$0451, conditional on pulse-profile modeling of Neutron Star Interior Composition Explorer (NICER) X-ray spectral-timing event data. We perform relativistic ray-tracing of thermal emission from hot regions of the pulsar's surface. We assume two distinct hot regions based on two clear pulsed components in the phase-folded pulse-profile data; we explore a number of forms (morphologies and topologies) for each hot region, inferring their parameters in addition to the stellar mass and radius. For the family of models considered, the evidence (prior predictive probability of the data) strongly favors a model that permits both hot regions to be located in the same rotational hemisphere. Models wherein both hot regions are assumed to be simply-connected circular single-temperature spots, in particular those where the spots are assumed to be reflection-symmetric with respect to the stellar origin, are strongly disfavored. For the inferred configuration, one hot region subtends an angular extent of only a few degrees (in spherical coordinates with origin at the stellar center) and we are insensitive to other structural details; the second hot region is far more azimuthally extended in the form of a narrow arc, thus requiring a larger number of parameters to describe. The inferred mass $M$ and equatorial radius $R_\mathrm{eq}$ are, respectively, $1.34_{-0.16}^{+0.15}$ M$_{\odot}$ and $12.71_{-1.19}^{+1.14}$ km, whilst the compactness $GM/R_\mathrm{eq}c^2 = 0.156_{-0.010}^{+0.008}$ is more tightly constrained; the credible interval bounds reported here are approximately the $16\%$ and $84\%$ quantiles in marginal posterior mass., Comment: Appears in ApJ Letters Focus Issue on NICER Constraints on the Dense Matter Equation of State; 76 pages, 24 figures, 7 tables, 8 figure sets (available in the online journal or from the authors)

Neutron stars are not only of astrophysical interest, but are also of great interest to nuclear physicists, because their attributes can be used to determine the properties of the dense matter in their cores. One of the most informative approaches for determining the equation of state of this dense matter is to measure both a star's equatorial circumferential radius $R_e$ and its gravitational mass $M$. Here we report estimates of the mass and radius of the isolated 205.53 Hz millisecond pulsar PSR J0030+0451 obtained using a Bayesian inference approach to analyze its energy-dependent thermal X-ray waveform, which was observed using the Neutron Star Interior Composition Explorer (NICER). This approach is thought to be less subject to systematic errors than other approaches for estimating neutron star radii. We explored a variety of emission patterns on the stellar surface. Our best-fit model has three oval, uniform-temperature emitting spots and provides an excellent description of the pulse waveform observed using NICER. The radius and mass estimates given by this model are $R_e = 13.02^{+1.24}_{-1.06}$ km and $M = 1.44^{+0.15}_{-0.14}\ M_\odot$ (68%). The independent analysis reported in the companion paper by Riley et al. (2019) explores different emitting spot models, but finds spot shapes and locations and estimates of $R_e$ and $M$ that are consistent with those found in this work. We show that our measurements of $R_e$ and $M$ for PSR J0030$+$0451 improve the astrophysical constraints on the equation of state of cold, catalyzed matter above nuclear saturation density., Comment: 49 pages, 16 figures, part of The Astrophysical Journal Letters focus issue on the Neutron Star Interior Composition Explorer

This corrects the article DOI: 10.1103/PhysRevLett.121.091102.

Due to increased use of dried distillers grains with solubles (DDGS) in animal feed and accessibility of ethanol plants in the Midwest, this study evaluated the effect of feeding DDGS in place of soybean meal (SBM) on the fecal microbiome of Boer goats. Twenty-four Boer goat kids (apx. 70 d of age; 28.21 ± 0.96 kg) were blocked by BW and randomly assigned to 1 of 2 treatment diets for 47 d. Treatments were 0% (0DDGS) and 100% (30DDGS) DDGS in place of SBM. Goats were placed in 8 pens (4 pens/treatment; 3 goats/pen) with ad libitum access to feed and water. Fecal pellets were collected on d 47 via rectal grab and stored at -80°C until microbiome sequencing was performed. The V4 region of the 16S rRNA gene was sequenced by MR DNA (MR DNA, Shallowater, TX) on the Illumina HiSeq 2500 platform (Illumina, Inc., San Diego, CA). Data were analyzed using ANOVA with Tukey’s test for pairwise comparisons. Genera impacted by DDGS inclusion with individual relative abundances greater than 1% included increased Ruminococcus (P = 0.01) and Methanobrevibacter (P = 0.009) and decreased Lachnoclostridium (P = 0.02). Ruminococcus and Methanobrevibacter most likely increased in 30DDGS due to greater amounts of soluble fiber passing through the rumen, thus being fermented in the hindgut. The overall percentage of the phyla Bacteroidetes (P = 0.36) and Firmicutes (P = 0.12) did not differ between treatments; however, Firmicutes:Bacteroidetes increased (P = 0.05) in the 30DDGS diet. Treatment did not impact β-diversity (P = 0.47) although species richness increased (P = 0.09) in DDGS-fed goats as more soluble fiber was available for fermentation in the hindgut. In all, results of this study found replacing SBM with DDGS did not greatly alter the fecal microbiome of Boer goats.

Analytical formulas for next-to-leading order temperature corrections to the thermal state variables of interacting nucleons in bulk matter are derived in the degenerate limit. The formalism developed is applicable to a wide class of non-relativistic and relativistic models of hot and dense matter currently used in nuclear physics and astrophysics (supernovae, proto-neutron stars and neutron star mergers) as well as in condensed matter physics. We consider the general case of arbitrary dimensionality of momentum space and an arbitrary degree of relativity (for relativistic mean-field theoretical models). For non-relativistic zero-range interactions, knowledge of the Landau effective mass suffices to compute next-to-leading order effects, but in the case of finite-range interactions, momentum derivatives of the Landau effective mass function up to second order are required. Numerical computations are performed to compare results from our analytical formulas with the exact results for zero- and finite-range potential and relativistic mean-field theoretical models. In all cases, inclusion of next-to-leading order temperature effects substantially extends the ranges of partial degeneracy for which the analytical treatment remains valid., 28 pages, 8 figures

We use gravitational-wave observations of the binary neutron star merger GW170817 to explore the tidal deformabilities and radii of neutron stars. We perform Bayesian parameter estimation with the source location and distance informed by electromagnetic observations. We also assume that the two stars have the same equation of state; we demonstrate that for stars with masses comparable to the component masses of GW170817, this is effectively implemented by assuming that the stars' dimensionless tidal deformabilities are determined by the binary's mass ratio $q$ by $\Lambda_1/\Lambda_2 = q^6$. We investigate different choices of prior on the component masses of the neutron stars. We find that the tidal deformability and 90$\%$ credible interval is $\tilde{\Lambda}=222^{+420}_{-138}$ for a uniform component mass prior, $\tilde{\Lambda}=245^{+453}_{-151}$ for a component mass prior informed by radio observations of Galactic double neutron stars, and $\tilde{\Lambda}=233^{+448}_{-144}$ for a component mass prior informed by radio pulsars. We find a robust measurement of the common areal radius of the neutron stars across all mass priors of $8.9 \le \hat{R} \le 13.2$ km, with a mean value of $\langle \hat{R} \rangle = 10.8$ km. Our results are the first measurement of tidal deformability with a physical constraint on the star's equation of state and place the first lower bounds on the deformability and areal radii of neutron stars using gravitational waves., Comment: Main paper: 6 pages, 3 figures; Supplemental Material: 5 pages, 6 figures, Erratum 2 pages, 1 figure

Finite size effects in a neutron star merger are manifested, at leading order, through the tidal deformabilities of the stars. If strong first-order phase transitions do not exist within neutron stars, both neutron stars are described by the same equation of state, and their tidal deformabilities are highly correlated through their masses even if the equation of state is unknown. If, however, a strong phase transition exists between the central densities of the two stars, so that the more massive star has a phase transition and the least massive star does not, this correlation will be weakened. In all cases, a minimum deformability for each neutron star mass is imposed by causality, and a less conservative limit is imposed by the unitary gas constraint, both of which we compute. In order to make the best use of gravitational wave data from mergers, it is important to include the correlations relating the deformabilities and the masses as well as lower limits to the deformabilities as a function of mass. Focusing on the case without strong phase transitions, and for mergers where the chirp mass $\mathcal{M}\ensuremath{\le}1.4\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$, which is the case for all observed double neutron star systems where a total mass has been accurately measured, we show that the ratio of the dimensionless tidal deformabilities satisfy ${\mathrm{\ensuremath{\Lambda}}}_{1}/{\mathrm{\ensuremath{\Lambda}}}_{2}\ensuremath{\sim}{q}^{6}$, where $q={M}_{2}/{M}_{1}$ is the binary mass ratio; $\mathrm{\ensuremath{\Lambda}}$ and $M$ are the dimensionless deformability and mass of each star, respectively. Moreover, they are bounded by ${q}^{{n}_{\ensuremath{-}}}\ensuremath{\ge}{\mathrm{\ensuremath{\Lambda}}}_{1}/{\mathrm{\ensuremath{\Lambda}}}_{2}\ensuremath{\ge}{q}^{{n}_{0+}+q{n}_{1+}}$, where ${n}_{\ensuremath{-}}l{n}_{0+}+q{n}_{1+}$; the parameters depend only on $\mathcal{M}$, which is accurately determined from the gravitational-wave signal. We also provide analytic expressions for the wider bounds that exist in the case of a strong phase transition. We argue that bounded ranges for ${\mathrm{\ensuremath{\Lambda}}}_{1}/{\mathrm{\ensuremath{\Lambda}}}_{2}$, tuned to $\mathcal{M}$, together with lower bounds to $\mathrm{\ensuremath{\Lambda}}(M)$, will be more useful in gravitational waveform modeling than other suggested approaches.