119265603
Submillimeter / millimeter observations of the molecular clouds associated with Tycho’s supernova remnant
We have carried out CO J = 2 - 1 and CO J = 3 - 2 observations toward Tycho's supernova remnant (SNR) using the KOSMA 3m-telescope. From these observations, we identified three molecular clouds (MCs) around the SNR. The small cloud in the southwest was discovered for the first time. In the north and east, two MCs (Cloud A and Cloud B) adjacent in space display a bow-shaped morphology, and have broad emission lines, which provide some direct evidences of the SNR-MCs interaction. The MCs are revealed at -69~ -59 km s -1 , coincident with Tycho's SNR. The MCs associated with Tycho's SNR have a mass of ~ 2.13 × 10 3 M ⊙ . Position-velocity diagrams show the two clouds to be adjacent in velocity, which means cloud-cloud collision could occur in this region. The maximum value (0.66 ± 0.10) of the integrated CO line intensity ratio (I CO J =3-2 /I CO J =2-1 ) for the three MCs agrees well with the previous measurement of individual Galactic MCs, implying that the SNR shock drove into the MCs. The two MCs have a line intensity ratio gradient. The distribution of the ratio appears to indicate that the shock propagates from the southwest to the northeast.
119269296
Outflow and accretion detections in the young stellar object IRAS 04579+4703
We present Submillimeter Array observations of the young stellar object IRAS 04579+4703 in the 1.3 mm continuum and in the 12 CO(2−1), 13 CO(2−1), and C 18 O(2−1) lines. The 1.3 mm continuum image reveals a flattened structure with a mass of 13 M � . The 12 CO(2−1) line map and position-velocity diagram, together with the broad wing (full width = 30 km s −1 )o f the 12 CO(2−1) line, clearly show that there is an outflow motion, which originates from an embedded massive YSO in this region. The lengths of the blue-shifted and red-shifted lobes are 0.14 pc and 0.13 pc, respectively. The total gas mass, average dynamical timescale, and
118385674
A systemic study of 14 southern infrared dark clouds with N2H+, HNC, HCO+ and HCN lines
We have studied 14 southern infrared dark clouds (IRDCs) using the data taken from the Millimetre Astronomy Legacy Team 90 GHz (MALT90) survey and the GLIMPSE and MIPSGAL mid-infrared survey of the inner Galaxy. The physical and chemical characteristics of the 14 IRDCs are investigated using N2H+(1-0), HNC(1-0), HCO+(1-0), and HCN(1-0) molecular lines. We find that the 14 IRDCs are in different evolutionary stages from the "starless" to the sources with an UCHII region. Three IRDCs are detected to have the star forming activities. The integrated intensity ratios I(HCO+)/I(HCN), I(N2H+)/I(HCN), and I(HNC)/I(HCN) are all about 1.5, which is different from the previous measurements, suggesting that the integrated intensity ratios may be affected by the cloud environments. The integrated intensities of HNC, HCO+ and HCN show a tight correlation for the 14 IRDCs, implying a close link to the chemical evolution of these three species in the IRDCs. The derived excitation temperature for each IRDC is less than 25 K. We estimate the abundances of the four molecules from 10^(-11) to 10^(-9), and the average abundance ratios N(HNC)/N(HCN) = 1.4+ -0.50, N(HNC)/N(HCO+) = 1.74 + - 0.22, N(HCN)/N(HCO+)= 1.21 + - 0.41.
119114895
The open cluster NGC 6823 and possible triggered star formation associated with SNR G59.5+0.1
Aims. We investigate the environment in the vicinity of the supernova remnant (SNR) G59.5+0.1 and identify all the young stellar objects (YSOs) around the SNR, to derive the physical properties, obtain insight into the star-formation history, and determine whether SNR G59.5+0.1 can trigger star formation in this region. Methods. We perform the submillimeter/millimeter observations in CO lines toward the southeast of SNR G59.5+0.1 with the KOSMA 3 m Telescope. High values of the integrated CO line-intensity ratio RICO(3−2)/ICO(2−1) is identified as one good signature of the SNR-MC (molecular cloud) interacting system. To investigate the impact of SNR G59.5+0.1 on the process of star formation, we use GLIMPSE I catalog to select YSOs (including Class I and Class II sources). Results. The CO emission forming an arc-like shape and mid-infrared 8.28 μm emission are coincident with SNR G59.5+0.1, which ‐ ‐
119117591
PROPERTIES AND KEPLERIAN ROTATION OF THE HOT CORE IRAS 20126+4104
We present Submillimeter Array (SMA) observations of the massive star-forming region IRAS 20126+4104 in the millimeter continuum and in several molecular line transitions. With the SMA data, we have detected nine molecular transitions, including deuterated hydrogen cyanide, CH{sub 3}OH, H{sub 2}CO, and HC{sub 3}N molecules, and imaged each molecular line. From the 1.3 mm continuum emission a compact millimeter source is revealed, which is also associated with H{sub 2}O, OH, and CH{sub 3}OH masers. Using a rotation temperature diagram, we derive that the rotational temperature and the column density of CH{sub 3}OH are 200 K and 3.7 Multiplication-Sign 10{sup 17} cm{sup -2}, respectively. The calculated results and analysis further indicate that a hot core coincides with IRAS 20126+4104. The position-velocity diagrams of H{sub 2}CO (3{sub 0,3}-2{sub 0,2}) and HC{sub 3}N (25-24) clearly present Keplerian rotation. Moreover, H{sub 2}CO (3{sub 0,3}-2{sub 0,2}) is found to trace the disk rotation for the first time.
119242109
Molecular clumps and star formation associated with the infrared dust bubble N131
Aims. The aim is to explore the interstellar medium around the dust bubble N131 and search for signatures of star formation. 
Methods. We perform a multiwavelength study around the N131 with data taken from large-scale surveys of infrared observation with online archive. We present new observations of three CO J = 1 - 0 isotope variants from Purple Mountain Observatory 13.7 m telescope. We analyze the distribution of the molecular gas and dust in the environment of the N131. We use color-color diagrams to search for young stellar objects and identify exciting star candidates. 
Results. The kinematic distance of about 8.6 kpc has been adopted as the distance of the bubble N131 from the Sun in this work. We have found a ring of clouds in CO emission coincident with the shell of N131 seen in the Spitzer telescope images, and two giant elongated molecular clouds of CO emission appearing on opposite sides of the ringlike shell of N131. There is a cavity within bubble at 1.4 GHz and 24 {\mu}m. Seven IRAS point sources are distributed along the ringlike shell of the bubble N131. 15 exciting stars and 63 YSOs candidates have been found. The clustered class I and II YSOs are distributed along the elongated clouds in the line of sight.
116266412
Nuclear constraints on the core-crust transition density and pressure of neutron stars
Using the equation of state of asymmetric nuclear matter that has been recently constrained by the isospin diffusion data from intermediate-energy heavy ion collisions, we have studied the transition density and pressure at the inner edge of neutron star crusts, and they are found to be 0.040 fm^{-3} <= \rho_{t}<= 0.065 fm^{-3} and 0.01 MeV/fm^{3} <= P_{t} <= 0.26 MeV/fm^{3}, respectively, in both the dynamical and thermodynamical approaches. We have further found that the widely used parabolic approximation to the equation of state of asymmetric nuclear matter gives significantly higher values of core-crust transition density and pressure, especially for stiff symmetry energies. With these newly determined transition density and pressure, we have obtained an improved relation between the mass and radius of neutron stars based on the observed minimum crustal fraction of the total moment of inertia for Vela pulsar.
119164414
Nuclear constraints on non-Newtonian gravity at femtometer scale
Effects of the non-Newtonian gravity on properties of finite nuclei are studied by consistently incorporating both the direct and exchange contribution of the Yukawa potential in the Hartree–Fock approach using a well-tested Skyrme force for the strong interaction. It is shown for the first time that the strength of the Yukawa term in the non-Newtonian gravity is limited to log (|α|) < 1.75/[λ(fm)]0.54 + 33.6 within the length scale of λ = 1 − 10 fm in order for the calculated properties of finite nuclei not to be in conflict with accurate experimental data available.
119293513
Disentangling effects of collision geometry and symmetry energy in U+U collisions
Effects of the collision geometry on experimental observables that are known to be sensitive to the high-density behavior of nuclear symmetry energy are examined in U+U collisions at 0.52 GeV/nucleon using an isospin- and momentum-dependent interaction within the framework of IBUU transport model. It is found that the neutron-proton differential flow in tip-tip collisions and the difference of neutron and proton elliptic flow in body-body collisions are more sensitive to the symmetry energy at supra-saturation densities compared with collisions of spherical nuclei of the same masses. In addition, the n/p ratio of pre-equilibrium nucleons is found to be slightly more sensitive to the symmetry energy in tip-tip collisions, and the collision geometry affects the \pi^-/\pi^+ ratio significantly.
119184097
Imprints of Nuclear Symmetry Energy on Properties of Neutron Stars
Significant progress has been made in recent years in constraining the density dependence of nuclear symmetry energy using terrestrial nuclear laboratory data. Around and below the nuclear matter saturation density, the experimental constraints start to merge in a relatively narrow region. At supra-saturation densities, there are, however, still large uncertainties. After summarizing the latest experimental constraints on the density dependence of nuclear symmetry energy, we highlight a few recent studies examining imprints of nuclear symmetry energy on the binding energy, energy release during hadron-quark phase transitions as well as the ω-mode frequency and damping time of gravitational wave emission of neutron stars.
118723617
Constraining the EOS of Neutron-Rich Nuclear Matter and Properties of Neutron Stars with Heavy-Ion Reactions
Heavy‐ion reactions especially those induced by radioactive beams provide useful information about the density dependence of the nuclear symmetry energy, thus the Equation of State of neutron‐rich nuclear matter, relevant for many astrophysical studies. The latest developments in constraining the symmetry energy at both sub‐ and supra‐saturation densities from analyses of the isopsin diffusion and the π−/π+ ratio in heavy‐ion collisions using the IBUU04 transport model are discussed. Astrophysical ramifications of the partially constrained symmetry energy on properties of neutron star crusts, gravitational waves emitted by deformed pulsars and the w‐mode oscillations of neutron stars are presented briefly.