We present extensive multiwavelength (radio to X-ray) observations of the Type Ib/c SN 2013ge from −13 to +457 days relative to maximum light, including a series of optical spectra and Swift UVoptical photometry beginning 2 − 4 days post-explosion. This data set makes SN 2013ge one of the best observed normal Type Ib/c SN at early times-when the light curve is particularly sensitive to the progenitor configuration and mixing of radioactive elements-and reveals two distinct light curve components in the UV bands. The first component rises over 4 − 5 days and is visible for the first week post-explosion. Spectra of the first component have blue continua and show a plethora of moderately high-velocity (∼15,000 km s −1 ) but narrow (∼3500 km s −1 ) spectroscopic features, indicating that the line-forming region is restricted. The explosion parameters estimated for the bulk explosion (M ej ∼ 2 − 3 M ⊙ ; E K ∼ 1 − 2 ×10 51 erg) are standard for Type Ib/c SN, and there is evidence for weak He features at early times-in an object which would have otherwise been classified as Type Ic. In addition, SN 2013ge exploded in a low metallicity environment (∼0.5 Z ⊙ ) and we have obtained some of the deepest radio and X-ray limits for a Type Ib/c SN to date, which constrain the progenitor mass-loss rate to beṀ < 4 × 10 −6 M ⊙ yr −1 . We are left with two distinct progenitor scenarios for SN 2013ge, depending on our interpretation of the early emission. If the first component is cooling envelope emission, then the progenitor of SN 2013ge either possessed an extended ( 30 R ⊙ ) envelope or ejected a portion of its envelope in the final 1 year before core-collapse. Alternatively, if the first component is due to outwardly mixed 56 Ni, then our observations are consistent with the asymmetric ejection of a distinct clump of nickel-rich material at high velocities. Current models for the collision of a SN shock with a binary companion cannot reproduce both the timescale and luminosity of the early emission in SN 2013ge. Finally, the spectra of the first component of SN 2013ge are similar to those of the rapidly-declining SN 2002bj.
Vertical coordination is a more comprehensive concept than vertical integration, capturing market, contractual, and ownership coordination. Williamson suggests that transaction costs motivate the use of nonmarket arrangements to vertically coordinate production. This paper presents a vertical coordination index incorporating industry input‐output relationships and nonmarket arrangements. In an econometric analysis, the vertical coordination index is utilized to examine transaction cost effects on food industry vertical linkages. Empirical results support the hypothesis that transaction costs are a primary motivation to vertically coordinate via nonmarket arrangements. Results also suggest the vertical coordination index is more robust than traditional vertical integration measure.
The All-Sky Automated Survey for Supernovae (ASAS-SN) is the only project in existence to scan the entire sky in optical light every ∼day, reaching a depth of g ∼ 18 mag. Over the course of its first four years of transient alerts (2013)(2014)(2015)(2016), ASAS-SN observed 53 events classified as likely M dwarf flares. We present follow-up photometry and spectroscopy of all 53 candidates, confirming flare events on 47 M dwarfs, one K dwarf, and one L dwarf. The remaining four objects include a previously identified TT Tauri star, a young star with outbursts, and two objects too faint to confirm. A detailed examination of the 49 flare star light curves revealed an additional six flares on five stars, resulting in a total of 55 flares on 49 objects ranging in V -band contrast from ∆V = −1 to −10.2 mags. Using an empirical flare model to estimate the unobserved portions of the flare light curve, we obtain lower limits on the V -band energy emitted during each flare, spanning log(E V /ergs) = 32 to 35, which are among the most energetic flares detected on M dwarfs. The ASAS-SN M-dwarf flare stars show a higher fraction of Hα emission as well as stronger Hα emission compared to M dwarfs selected without reference to activity, consistent with belonging to a population of more magnetically active sjschmidt@aip.de stars. We also examined the distribution of tangential velocities, finding that the ASAS-SN flaring M dwarfs are likely to be members of the thin disk and are neither particularly young nor old.
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