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  • 1
    Electronic Resource
    Electronic Resource
    Self-report visual scale of course appeal (1992)
    Springer
    Higher education 23 (1992), S. 321-329 
    Details
    ISSN: 1573-174X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Abstract A 4-item affect scale portrayed on crosswise lines was developed and tested on medical students participating in preclinical courses with a view to measuring appeal as an educational outcome. This usage was based on assumptions that end-of-course adaptation could be derived from affect responses and should reflect the appeal of a course experience. Indeed, the results demonstrated that positive affect (pleasure, satisfaction) and negative affect (anxiety, grief) responses have substantial correlations with an independent measure of appeal: course valuing section scores of the Course Valuing Inventory. Moreover, students with various adaptation modes, as signalled by affect response patterns, showed significantly different means in course valuing scores. Significant differences were also shown in adaptation mode distribution among students finishing courses with distinct integration methods, or levels of learner control. As hypothesized, it was found that end-of-course adaptation modes differentiate between learners who do and do not volunteer for a student preceptorship in the same course. Findings suggest that affect responses can be used as a scale of course appeal to measure the effects of motivational strategies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00145020
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  • 2
    Electronic Resource
    Electronic Resource
    The problem-based Learning Approach as an enhancement factor of personal meaningfulness of learning (1995)
    Springer
    Higher education 29 (1995), S. 93-101 
    Details
    ISSN: 1573-174X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Abstract Does the problem-based learning (PBL) approach contribute to personally meaningful learning? This study used a double-cohort design to explore the question by focusing a PBL singlecourse, which was compared to a conventional one. Consecutive sampling of medical students was obtained for both groups. Student outcomes measured were Course Valuing Inventory (CVI), affect, and preceptorship appeal responses. Paired tests showed significant increases in CVI scores from start to end of term in the PBL group only. Significant trends were observed in the relationships between experiencing the PBL approach and CVI score level, positive affect mode, and strength of preceptorship appeal. Stratified analysis did not detect confounding effects on the outcome measures from background course experience, learners' characteristics, or time trend. The findings suggest that the PBL approach can improve the quality of the learning environment in both cognitive and emotional ways for most students.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01384243
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  • 3
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    Evolution of the H {beta} + [O III] and [O II] luminosity functions and the [O II] star formation history of the Universe up to z ~ 5 from HiZELS (2015)
    Oxford University Press
    Details
    Publication Date: 2015-08-12
    Description: We investigate the evolution of the H β + [O iii ] and [O ii ] luminosity functions from z  ~ 0.8 to ~5 in four redshift slices per emission line using data from the High- z Emission Line Survey (HiZELS). This is the first time that the H β + [O iii ] and [O ii ] luminosity functions have been studied at these redshifts in a self-consistent analysis. This is also the largest sample of [O ii ] and H β + [O iii ] emitters (3475 and 3298 emitters, respectively) in this redshift range, with large comoving volumes ~1  x  10 6  Mpc –3 in two independent volumes (COSMOS and UDS), greatly reducing the effects of cosmic variance. The emitters were selected by a combination of photometric redshift and colour–colour selections, as well as spectroscopic follow-up, including recent spectroscopic observations using DEIMOS and MOSFIRE on the Keck Telescopes and FMOS on Subaru. We find a strong increase in L * and a decrease in * for both H β + [O iii ] and [O ii ] emitters. We derive the [O ii ] star formation history of the Universe since z  ~ 5 and find that the cosmic star formation rate density (SFRD) rises from z  ~ 5 to ~3 and then drops towards z  ~ 0. We also find that our star formation history is able to reproduce the evolution of the stellar mass density up to z  ~ 5 based only on a single tracer of star formation. When comparing the H β + [O iii ] SFRDs to the [O ii ] and H α SFRD measurements in the literature, we find that there is a remarkable agreement, suggesting that the H β + [O iii ] sample is dominated by star-forming galaxies at high- z rather than AGNs.
    Print ISSN: 0035-8711
    Electronic ISSN: 1365-2966
    Topics: Physics
    Published by Oxford University Press
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  • 4
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    A large narrow-band H{alpha} survey at z~ 0.2: the bright end of the luminosity function, cosmic variance and clustering across cosmic time (2015)
    Oxford University Press
    Details
    Publication Date: 2015-08-15
    Description: We have carried out the largest (〉3.5  x  10 5  Mpc 3 , 26 deg 2 ) Hα narrow-band survey to date at z  ~ 0.2 in the SA22, W2 and XMMLSS extragalactic fields. Our survey covers a large enough volume to overcome cosmic variance and to sample bright and rare Hα emitters up to an observed luminosity of ~10 42.4  erg s –1 , equivalent to ~11 M  yr –1 . Using our sample of 220 sources brighter than 〉10 41.4  erg s –1 (〉1 M  yr –1 ), we derive Hα luminosity functions, which are well described by a Schechter function with * = 10 –2.85 ± 0.03  Mpc –3 and $L^*_\mathrm{H\alpha } = 10^{41.71\pm 0.02}$  erg s –1 (with a fixed faint end slope α = –1.35). We find that surveys probing smaller volumes (~3  x  10 4  Mpc 3 ) are heavily affected by cosmic variance, which can lead to errors of over 100 per cent in the characteristic density and luminosity of the Hα luminosity function. We derive a star formation rate density of SFRD  = 0.0094 ± 0.0008 M  yr –1 , in agreement with the redshift-dependent Hα parametrization from Sobral et al. The two-point correlation function is described by a single power law () = (0.159 ± 0.012) (–0.75 ± 0.05) , corresponding to a clustering length of r 0  = 3.3 ± 0.8 Mpc  h –1 . We find that the most luminous Hα emitters at z  ~ 0.2 are more strongly clustered than the relatively fainter ones. The $L^*_\mathrm{H\alpha }$ Hα emitters at z  ~ 0.2 in our sample reside in ~10 12.5–13.5 M dark matter haloes. This implies that the most star-forming galaxies always reside in relatively massive haloes or group-like environments and that the typical host halo mass of star-forming galaxies is independent of redshift if scaled by $L_\mathrm{H\alpha }/L^*_\mathrm{H\alpha }(z)$ , as proposed by Sobral et al.
    Print ISSN: 0035-8711
    Electronic ISSN: 1365-2966
    Topics: Physics
    Published by Oxford University Press
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  • 5
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    The brightest Ly {alpha} emitter: Pop III or black hole? (2015)
    Oxford University Press
    Details
    Publication Date: 2015-09-27
    Description: CR7 is the brightest z  = 6.6 Ly α emitter (LAE) known to date, and spectroscopic follow-up by Sobral et al. suggests that CR7 might host Population (Pop) III stars. We examine this interpretation using cosmological hydrodynamical simulations. Several simulated galaxies show the same ‘Pop III wave’ pattern observed in CR7. However, to reproduce the extreme CR7 Ly α/He ii 1640 line luminosities ( $L_{\rm \alpha /He\,\small {II}}$ ) a top-heavy initial mass function and a massive ( 10 7 M ) Pop III burst with age 2 Myr are required. Assuming that the observed properties of Ly α and He ii emission are typical for Pop III, we predict that in the COSMOS/UDS/SA22 fields, 14 out of the 30 LAEs at z  = 6.6 with L α  〉 10 43.3 erg s –1 should also host Pop III stars producing an observable $L_{\rm He\,\small {II}}\gtrsim 10^{42.7}\,{\rm erg}\,{\rm s}^{-1}$ . As an alternate explanation, we explore the possibility that CR7 is instead powered by accretion on to a direct collapse black hole. Our model predicts L α , $L_{\rm He\,\small {II}}$ , and X-ray luminosities that are in agreement with the observations. In any case, the observed properties of CR7 indicate that this galaxy is most likely powered by sources formed from pristine gas. We propose that further X-ray observations can distinguish between the two above scenarios.
    Print ISSN: 0035-8711
    Electronic ISSN: 1365-2966
    Topics: Physics
    Published by Oxford University Press
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  • 6
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    Identification of the brightest Ly{alpha} emitters at z = 6.6: implications for the evolution of the luminosity function in the reionization era (2015)
    Oxford University Press
    Details
    Publication Date: 2015-05-30
    Description: Using wide-field narrow-band surveys, we provide a new measurement of the z  = 6.6 Lymanα emitter (LAE) luminosity function (LF), which constraints the bright end for the first time. We use a combination of archival narrow-band NB 921 data in UDS and new NB 921 measurements in SA22 and COSMOS/UltraVISTA, all observed with the Subaru telescope, with a total area of ~5 deg 2 . We exclude lower redshift interlopers by using broad-band optical and near-infrared photometry and also exclude three supernovae with data split over multiple epochs. Combining the UDS and COSMOS samples, we find no evolution of the bright end of the Lyα LF between z  = 5.7 and 6.6, which is supported by spectroscopic follow-up, and conclude that sources with Himiko -like luminosity are not as rare as previously thought, with number densities of ~1.5 10 –5  Mpc –3 . Combined with our wide-field SA22 measurements, our results indicate a non-Schechter-like bright end of the LF at z  = 6.6 and a different evolution of observed faint and bright LAEs, overcoming cosmic variance. This differential evolution is also seen in the spectroscopic follow-up of UV-selected galaxies and is now also confirmed for LAEs, and we argue that it may be an effect of reionization. Using a toy model, we show that such differential evolution of the LF is expected, since brighter sources are able to ionize their surroundings earlier, such that Lyα photons are able to escape. Our targets are excellent candidates for detailed follow-up studies and provide the possibility to give a unique view on the earliest stages in the formation of galaxies and reionization process.
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    Electronic ISSN: 1365-2966
    Topics: Physics
    Published by Oxford University Press
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  • 7
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    [O III] emission line as a tracer of star-forming galaxies at high redshifts: comparison between H{alpha} and [O III] emitters at z=2.23 in HiZELS (2016)
    Oxford University Press
    Details
    Publication Date: 2016-07-31
    Description: We investigate the properties of z  = 2.23 Hα and [O iii ] 5007 emitters using the narrow-band-selected samples obtained from the High- z Emission Line Survey. We construct two samples of the Hα and [O iii ] emitters and compare their integrated physical properties. We find that the distribution of stellar masses, dust extinction, star formation rates (SFRs), and specific SFRs (sSFRs) is not statistically different between the two samples. When we separate the full galaxy sample into three subsamples according to the detections of the Hα and/or [O iii ] emission lines, most of the sources detected with both Hα and [O iii ] show log(sSFR UV ) –9.5. The comparison of the three subsamples suggests that sources with strong [O iii ] line emission tend to have the highest star-forming activity out all galaxies that we study. We argue that the [O iii ] emission line can be used as a tracer of star-forming galaxies at high redshift, and that it is especially useful to investigate star-forming galaxies at z  〉 3, for which Hα emission is no longer observable from the ground.
    Print ISSN: 0035-8711
    Electronic ISSN: 1365-2966
    Topics: Physics
    Published by Oxford University Press
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  • 8
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    The rise and fall of star formation in z ~ 0.2 merging galaxy clusters (2015)
    Oxford University Press
    Details
    Publication Date: 2015-04-26
    Description: CIZA J2242.8+5301 (‘Sausage’) and 1RXS J0603.3+4213 (‘Toothbrush’) are two low-redshift ( z ~ 0.2), massive (~2 10 15 M ), post-core passage merging clusters, which host-shock waves traced by diffuse radio emission. To study their star formation properties, we uniformly survey the ‘Sausage’ and ‘Toothbrush’ clusters in broad- and narrow-band filters and select a sample of 201 and 463 line emitters, down to a rest-frame equivalent width (13 Å). We robustly separate between Hα and higher redshift emitters using a combination of optical multiband ( B , g , V , r , i , z ) and spectroscopic data. We build Hα luminosity functions for the entire cluster region, near the shock fronts, and away from the shock fronts and find striking differences between the two clusters. In the dynamically younger, 1 Gyr old ‘Sausage’ cluster we find numerous (59) Hα emitters above a star formation rate (SFR) of 0.17 M  yr –1 surprisingly located in close proximity to the shock fronts, embedded in very hot intracluster medium plasma. The SFR density for the cluster population is at least at the level of typical galaxies at z ~ 2. Down to the same SFR, the possibly dynamically more evolved ‘Toothbrush’ cluster has only nine Hα galaxies. The cluster Hα galaxies fall on the SFR–stellar mass relation z ~ 0.2 for the field. However, the ‘Sausage’ cluster has an Hα emitter density 〉20 times that of blank fields. If the shock passes through gas-rich cluster galaxies, the compressed gas could collapse into dense clouds and excite star formation for a few 100 Myr. This process ultimately leads to a rapid consumption of the molecular gas, accelerating the transformation of gas-rich field spirals into cluster S0s or ellipticals.
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    Electronic ISSN: 1365-2966
    Topics: Physics
    Published by Oxford University Press
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  • 9
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    CF-HiZELS, an ~10 deg2 emission-line survey with spectroscopic follow-up: H{alpha}, [O III] + H{beta} and [O II] luminosity functions at z = 0.8, 1.4 and 2.2 (2015)
    Oxford University Press
    Details
    Publication Date: 2015-06-15
    Description: We present results from the largest contiguous narrow-band survey in the near-infrared. We have used the wide-field infrared camera/Canada–France–Hawaii Telescope and the lowOH2 filter (1.187 ± 0.005 μm) to survey 10 deg 2 of contiguous extragalactic sky in the SA22 field. A total of ~6000 candidate emission-line galaxies are found. We use deep ugrizJK data to obtain robust photometric redshifts. We combine our data with the High-redshift(Z) Emission Line Survey (HiZELS), explore spectroscopic surveys (VVDS, VIPERS) and obtain our own spectroscopic follow-up with KMOS, FMOS and MOSFIRE to derive large samples of high-redshift emission-line selected galaxies: 3471 Hα emitters at z  = 0.8, 1343 [O iii ] + Hβ emitters at z  = 1.4 and 572 [O ii ] emitters at z  = 2.2. We probe comoving volumes of 〉10 6  Mpc 3 and find significant overdensities, including an 8.5 (spectroscopically confirmed) overdensity of Hα emitters at z  = 0.81. We derive Hα, [O iii ] + Hβ and [O ii ] luminosity functions at z  = 0.8, 1.4, 2.2, respectively, and present implications for future surveys such as Euclid . Our uniquely large volumes/areas allow us to subdivide the samples in thousands of randomized combinations of areas and provide a robust empirical measurement of sample/cosmic variance. We show that surveys for star-forming/emission-line galaxies at a depth similar to ours can only overcome cosmic-variance (errors 〈10 per cent) if they are based on volumes 〉5  x  10 5  Mpc 3 ; errors on L * and * due to sample (cosmic) variance on surveys probing ~10 4 and ~10 5  Mpc 3 are typically very high: ~300 and ~40–60 per cent, respectively.
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    Electronic ISSN: 1365-2966
    Topics: Physics
    Published by Oxford University Press
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  • 10
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    MC2: boosted AGN and star formation activity in CIZA J2242.8+5301, a massive post-merger cluster at z = 0.19 (2015)
    Oxford University Press
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    Publication Date: 2015-04-26
    Description: Cluster mergers may play a fundamental role in the formation and evolution of cluster galaxies. Stroe et al. revealed unexpected overdensities of candidate Hα emitters near the ~1-Mpc-wide shock fronts of the massive (~2 10 15  M ) ‘Sausage’ merging cluster, CIZA J2242.8+5301. We used the Keck/Deep Imaging Multi-Object Spectrograph and the William Herschel Telescope/AutoFib2+WYFFOS to confirm 83 Hα emitters in and around the merging cluster. We find that cluster star-forming galaxies in the hottest X-ray gas and/or in the cluster subcores (away from the shock fronts) show high [S ii ]6716/[S ii ]6761 and high [S ii ] 6716/Hα, implying very low electron densities (〈30 lower than all other star-forming galaxies outside the cluster) and/or significant contribution from supernovae, respectively. All cluster star-forming galaxies near the cluster centre show evidence of significant outflows (blueshifted Na D ~200–300 km s –1 ), likely driven by supernovae. Strong outflows are also found for the cluster Hα active galactic nucleus (AGN). Hα star-forming galaxies in the merging cluster follow the z  ~ 0 mass–metallicity relation, showing systematically higher metallicity (~0.15–0.2 dex) than Hα emitters outside the cluster (projected R  〉 2.5 Mpc). This suggests that the shock front may have triggered remaining metal-rich gas which galaxies were able to retain into forming stars. Our observations show that the merger of impressively massive (~10 15  M ) clusters can provide the conditions for significant star formation and AGN activity, but, as we witness strong feedback by star-forming galaxies and AGN (and given how massive the merging cluster is), such sources will likely quench in a few 100 Myr.
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    Topics: Physics
    Published by Oxford University Press
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