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<jats:title>Abstract</jats:title> <jats:p>During star formation, the accretion disk drives fast MHD winds, which usually contain two components, a collimated jet and a radially distributed wide-angle wind. These winds entrain the surrounding ambient gas producing molecular outflows. We report a recent observation of <jats:sup>12</jats:sup>CO (2–1) emission of the HH 46/47 molecular outflow by the Atacama Large Millimeter/submillimeter Array, in which we identify multiple wide-angle outflowing shell structures in both the blueshifted and redshifted outflow lobes. These shells are highly coherent in position–position–velocity space, extending to ≳40–50 km s<jats:sup>−1</jats:sup> in velocity and 10<jats:sup>4</jats:sup> au in space, with well-defined morphology and kinematics. We suggest these outflowing shells are the result of the entrainment of ambient gas by a series of outbursts from an intermittent wide-angle wind. Episodic outbursts in collimated jets are commonly observed, yet detection of a similar behavior in wide-angle winds has been elusive. Here we show clear evidence that the wide-angle component of the HH 46/47 protostellar outflows experiences variability similar to that seen in the collimated component.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Strongly lensed quasars with time-delay measurements are well known to provide the “time-delay distances” <jats:inline-formula> <jats:tex-math> <?CDATA ${D}_{{\rm{\Delta }}t}=(1+{z}_{L}){D}_{L}{D}_{S}/{D}_{{LS}}$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjab39e6ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>, and the angular diameter distances to the lens galaxies <jats:italic>D</jats:italic> <jats:sub> <jats:italic>L</jats:italic> </jats:sub>. These two kinds of distances give stringent constraints on cosmological parameters. In this work, we explore a different use of time-delay observables: under the assumption of a flat universe, strong lensing observations can accurately measure the angular diameter distances to the sources <jats:italic>D</jats:italic> <jats:sub> <jats:italic>S</jats:italic> </jats:sub>. The corresponding redshifts of the quasars may be up to <jats:italic>z</jats:italic> <jats:sub> <jats:italic>S</jats:italic> </jats:sub> ∼ 4 according to the forecast. The high-redshift distances would sample the Hubble diagram between SNe Ia and the cosmic microwave background, model-independently providing direct information on the evolution of the nature of our universe, for example, the dark energy equation of state parameter <jats:italic>w</jats:italic>(<jats:italic>z</jats:italic>). We apply our method to the existing lensing system SDSS 1206+4332 and get <jats:inline-formula> <jats:tex-math> <?CDATA ${D}_{S}={2388}_{-978}^{+2632}\,\mathrm{Mpc}$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjab39e6ieqn2.gif" xlink:type="simple" /> </jats:inline-formula> at <jats:italic>z</jats:italic> <jats:sub> <jats:italic>S</jats:italic> </jats:sub> = 1.789. We also make a forecast for the era of Large Synoptic Survey Telescope. The uncertainty of <jats:italic>D</jats:italic> <jats:sub> <jats:italic>S</jats:italic> </jats:sub> depends on the redshifts of the lens and the source, the uncertainties of <jats:italic>D</jats:italic> <jats:sub>Δ<jats:italic>t</jats:italic> </jats:sub> and <jats:italic>D</jats:italic> <jats:sub> <jats:italic>L</jats:italic> </jats:sub>, and the correlation between <jats:italic>D</jats:italic> <jats:sub>Δ<jats:italic>t</jats:italic> </jats:sub> and <jats:italic>D</jats:italic> <jats:sub> <jats:italic>L</jats:italic> </jats:sub>. Larger correlation would result in tighter <jats:italic>D</jats:italic> <jats:sub> <jats:italic>S</jats:italic> </jats:sub> determination.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The Low-Frequency Array radio telescope discovered the 707 Hz binary millisecond pulsar (MSP) J0952−0607 in a targeted radio pulsation search of an unidentified <jats:italic>Fermi</jats:italic> gamma-ray source. This source shows a weak energy flux of <jats:italic>F</jats:italic> <jats:sub> <jats:italic>γ</jats:italic> </jats:sub> = 2.6 × 10<jats:sup>−12</jats:sup> erg cm<jats:sup>−2</jats:sup> s<jats:sup>−1</jats:sup> in the energy range between 100 MeV and 100 GeV. Here we report the detection of pulsed gamma-ray emission from PSR J0952−0607 in a very sensitive gamma-ray pulsation search. The pulsar’s rotational, binary, and astrometric properties are measured over 7 years of <jats:italic>Fermi</jats:italic>-Large Area Telescope data. For this we take into account the uncertainty on the shape of the gamma-ray pulse profile. We present an updated radio-timing solution now spanning more than 2 years and show results from optical modeling of the black-widow-type companion based on new multiband photometric data taken with HiPERCAM on the Gran Telescopio Canarias on La Palma and ULTRACAM on the New Technology Telescope at ESO La Silla (based on observations collected at the European Southern Observatory, Chile; programme 0101.D-0925, PI: Clark, C. J.). PSR J0952−0607 is now the fastest-spinning pulsar for which the intrinsic spin-down rate has been reliably constrained (<jats:inline-formula> <jats:tex-math> <?CDATA ${\dot{P}}_{\mathrm{int}}\lesssim 4.6\times {10}^{-21}\,{\rm{s}}\,{{\rm{s}}}^{-1}$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjab357eieqn1.gif" xlink:type="simple" /> </jats:inline-formula>). The inferred surface magnetic field strength of <jats:inline-formula> <jats:tex-math> <?CDATA ${B}_{\mathrm{surf}}\lesssim 8.2\times {10}^{7}\,{\rm{G}}$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjab357eieqn2.gif" xlink:type="simple" /> </jats:inline-formula> is among the 10 lowest of all known pulsars. This discovery is another example of an extremely fast spinning black-widow pulsar hiding within an unidentified <jats:italic>Fermi</jats:italic> gamma-ray source. In the future such systems might help to pin down the maximum spin frequency and the minimum surface magnetic field strength of MSPs.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Coronal mass ejections (CMEs) often exhibit the classic three-part structure in a coronagraph, i.e., the bright front, dark cavity, and bright core, which are traditionally considered as the manifestations of coronal plasma pileup, magnetic flux rope (MFR), and filament, respectively. However, a recent survey based on 42 CMEs all possessing the three-part structure found that a large majority (69%) do not contain an eruptive filament at the Sun. Therefore, a challenging opinion is proposed and claims that the bright core can also correspond to the MFR, which is supported by the CME simulation. Then what is the nature of the CME core? In this paper, we address this issue through a CME associated with the eruption of a filament-hosting MFR on 2013 September 29. This CME exhibits the three-part morphology in multiple white-light coronagraphs from different perspectives. The new finding is that the bright core contains both a sharp and a fuzzy component. Through tracking the filament motion continuously from its source region to the outer corona, we conclude that the sharp component corresponds to the filament. The fuzzy component is suggested to result from the MFR that supports the filament against the gravity in the corona. Our study can shed more light on the nature of CME cores, and explain the core whether or not the filament is involved with a uniform scenario. The nature of the CME cavity is also discussed.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We present numerical modeling of particle acceleration at coronal shocks propagating through a streamer-like magnetic field by solving the Parker transport equation with spatial diffusion both along and across the magnetic field. We show that the location on the shock where the high-energy particle intensity is the largest, depends on the energy of the particles and on time. The acceleration of particles to more than 100 MeV mainly occurs in the shock-streamer interaction region, due to perpendicular shock geometry and the trapping effect of closed magnetic fields. A comparison of the particle spectra to that in a radial magnetic field shows that the intensity at 100 MeV (200 MeV) is enhanced by more than one order (two orders) of magnitude. This indicates that the streamer-like magnetic field can be an important factor in producing large solar energetic particle events. We also show that the energy spectrum integrated over the simulation domain consists of two different power laws. Further analysis suggests that it may be a mixture of two distinct populations accelerated in the streamer and open field regions, where the acceleration rate differs substantially. Our calculations also show that the particle spectra are affected considerably by a number of parameters, such as the streamer tilt angle, particle spatial diffusion coefficient, and shock compression ratio. While the low-energy spectra agree well with standard diffusive shock acceleration theory, the break energy ranges from ∼1 MeV to ∼90 MeV and the high-energy spectra can extend to ∼1 GeV with a slope of ∼2–3.</jats:p>