Buying High Tech Products

Prior research on technology-intensive (TI) markets makes abstraction of the social context in which transactions take place. In contrast with this prior literature, the authors show that buyer-vendor transactions in TI markets are relationally and structurally embedded in an interfirm network. Their main premise is that buyers in TI markets prefer vendors with whom they can share a strong tie, and that in turn buyers want these vendors to share strong ties with their component manufacturers. This is an important addition to TI literature and to the on-going debate on the strength of ties in the sociology, management and marketing literatures. The authors also specifically consider how characteristics focal to TI markets, such as the know-how buyers possess or the pace of technological change they perceive, affect the extent to which buying behavior is relationally and structurally embedded. An empirical test in the computer network market shows good support for the developed theory.tie strength;embeddedness;buying behavior;conjoint analysis;technology-intensive markets

Empirical Tests Of Optimal Cognitive Distance

This article provides empirical tests of the hypothesis of ‘optimal cognitive distance’, proposed by Nooteboom (1999, 2000), in two distinct empirical settings. Variety of cognition, needed for learning, has two dimensions: the number of agents with different cognition, and differences in cognition between them (cognitive distance). The hypothesis is that in interfirm relationships optimal learning entails a trade-off between the advantage of increased cognitive distance for a higher novelty value of a partner’s knowledge, and the disadvantage of less mutual understanding. If the value of learning is the mathematical product of novelty value and understandability, it has an inverse-U shaped relation with cognitive distance, with an optimum level that yields maximal value of learning. With auxiliary hypotheses, the hypothesis is tested on interfirm agreements between pharmaceutical companies and biotech companies, as well as on interfirm agreements in ICT industries.innovation;organizational learning;ICT;biotechnology;alliances

The size-star formation relation of massive galaxies at 1.5<z<2.5

We study the relation between size and star formation activity in a complete sample of 225 massive (M > 5 x 10^10 Msun) galaxies at 1.5<z<2.5, selected from the FIREWORKS UV-IR catalog of the CDFS. Based on stellar population synthesis model fits to the observed restframe UV-NIR SEDs, and independent MIPS 24 micron observations, 65% of galaxies are actively forming stars, while 35% are quiescent. Using sizes derived from 2D surface brightness profile fits to high resolution (FWHM_{PSF}~0.45 arcsec) groundbased ISAAC data, we confirm and improve the significance of the relation between star formation activity and compactness found in previous studies, using a large, complete mass-limited sample. At z~2, massive quiescent galaxies are significantly smaller than massive star forming galaxies, and a median factor of 0.34+/-0.02 smaller than galaxies of similar mass in the local universe. 13% of the quiescent galaxies are unresolved in the ISAAC data, corresponding to sizes <1 kpc, more than 5 times smaller than galaxies of similar mass locally. The quiescent galaxies span a Kormendy relation which, compared to the relation for local early types, is shifted to smaller sizes and brighter surface brightnesses and is incompatible with passive evolution. The progenitors of the quiescent galaxies, were likely dominated by highly concentrated, intense nuclear star bursts at z~3-4, in contrast to star forming galaxies at z~2 which are extended and dominated by distributed star formation.Comment: 6 pages, 4 figures, accepted for publication in Ap

Star-Forming Galaxies at Cosmic Noon

Ever deeper and wider lookback surveys have led to a fairly robust outline of the cosmic star formation history, which culminated around z~2 -- a period often nicknamed "cosmic noon." Our knowledge about star-forming galaxies at these epochs has dramatically advanced from increasingly complete population censuses and detailed views of individual galaxies. We highlight some of the key observational insights that influenced our current understanding of galaxy evolution in the equilibrium growth picture: ∙ scaling relations between galaxy properties are fairly well established among massive galaxies at least out to z~2, pointing to regulating mechanisms already acting on galaxy growth; ∙ resolved views reveal that gravitational instabilities and efficient secular processes within the gas- and baryon-rich galaxies at z~2 play an important role in the early build-up of galactic structure; ∙ ever more sensitive observations of kinematics at z~2 are probing the baryon and dark matter budget on galactic scales and the links between star-forming galaxies and their likely descendants; ∙ towards higher masses, massive bulges, dense cores, and powerful AGN and AGN-driven outflows are more prevalent and likely play a role in quenching star formation. We outline emerging questions and exciting prospects for the next decade with upcoming instrumentation, including the James Webb Space Telescope and the next generation of Extremely Large Telescopes

Buying High Tech Products

Prior research on technology-intensive (TI) markets makes abstraction of the social context in which transactions take place. In contrast with this prior literature, the authors show that buyer-vendor transactions in TI markets are relationally and structurally embedded in an interfirm network. Their main premise is that buyers in TI markets prefer vendors with whom they can share a strong tie, and that in turn buyers want these vendors to share strong ties with their component manufacturers. This is an important addition to TI literature and to the on-going debate on the strength of ties in the sociology, management and marketing literatures. The authors also specifically consider how characteristics focal to TI markets, such as the know-how buyers possess or the pace of technological change they perceive, affect the extent to which buying behavior is relationally and structurally embedded. An empirical test in the computer network market shows good support for the developed theory

The KMOS^3D Survey: design, first results, and the evolution of galaxy kinematics from 0.7<z<2.7

We present the KMOS^3D survey, a new integral field survey of over 600 galaxies at 0.7<z<2.7 using KMOS at the Very Large Telescope (VLT). The KMOS^3D survey utilizes synergies with multi-wavelength ground and space-based surveys to trace the evolution of spatially-resolved kinematics and star formation from a homogeneous sample over 5 Gyrs of cosmic history. Targets, drawn from a mass-selected parent sample from the 3D-HST survey, cover the star formation-stellar mass ($M_*$) and rest-frame $(U-V)-M_*$ planes uniformly. We describe the selection of targets, the observations, and the data reduction. In the first year of data we detect Halpha emission in 191 $M_*=3\times10^{9}-7\times10^{11}$ Msun galaxies at z=0.7-1.1 and z=1.9-2.7. In the current sample 83% of the resolved galaxies are rotation-dominated, determined from a continuous velocity gradient and $v_{rot}/\sigma>1$, implying that the star-forming 'main sequence' (MS) is primarily composed of rotating galaxies at both redshift regimes. When considering additional stricter criteria, the Halpha kinematic maps indicate at least ~70% of the resolved galaxies are disk-like systems. Our high-quality KMOS data confirm the elevated velocity dispersions reported in previous IFS studies at z>0.7. For rotation-dominated disks, the average intrinsic velocity dispersion decreases by a factor of two from 50 km/s at z~2.3 to 25 km/s at z~0.9 while the rotational velocities at the two redshifts are comparable. Combined with existing results spanning z~0-3, disk velocity dispersions follow an approximate (1+z) evolution that is consistent with the dependence of velocity dispersion on gas fractions predicted by marginally-stable disk theory.Comment: 20 pages, 11 figures, 1 Appendix; Accepted to ApJ November 2

The Far-Infrared, UV and Molecular Gas Relation in Galaxies up to z=2.5

We use the infrared excess (IRX) FIR/UV luminosity ratio to study the relation between the effective UV attenuation (A_IRX) and the UV spectral slope (beta) in a sample of 450 1<z<2.5 galaxies. The FIR data is from very deep Herschel observations in the GOODS fields that allow us to detect galaxies with SFRs typical of galaxies with log(M)>9.3. Thus, we are able to study galaxies on and even below the main SFR-stellar mass relation (main sequence). We find that main sequence galaxies form a tight sequence in the IRX--beta plane, which has a flatter slope than commonly used relations. This slope favors a SMC-like UV extinction curve, though the interpretation is model dependent. The scatter in the IRX-beta plane, correlates with the position of the galaxies in the SFR-M plane. Using a smaller sample of galaxies with CO gas masses, we study the relation between the UV attenuation and the molecular gas content. We find a very tight relation between the scatter in the IRX-beta plane and the specific attenuation (S_A), a quantity that represents the attenuation contributed by the molecular gas mass per young star. S_A is sensitive to both the geometrical arrangement of stars and dust, and to the compactness of the star forming regions. We use this empirical relation to derive a method for estimating molecular gas masses using only widely available integrated rest-frame UV and FIR photometry. The method produces gas masses with an accuracy between 0.12-0.16 dex in samples of normal galaxies between z~0 and z~1.5. Major mergers and sub-millimeter galaxies follow a different S_A relation.Comment: 11 pages, 6 pages appendix, 11 figures, accepted to Ap