169 research outputs found
Turkish teachers' beliefs regarding moral psychology and implicit moral education: a case study
This thesis reports a mixed method case study of Turkish teachersâ and trainee teachersâ beliefs and attitudes regarding aspects of moral education and moral psychology, and the development of these beliefs and attitudes through teacher training and experience. Both internationally and in Turkey it is generally agreed that teachers are not well enough equipped to carry out moral education. This thesis explores a philosophical argument for why understanding the psychology of moral development could be valuable for teachers in informing their engagement with explicit and implicit moral education. A cross-sectional sample of participants was investigated using a mix of quantitative and qualitative approaches to analyse beliefs and attitudes relevant to moral education. The results indicate that Turkish teachers and trainee teachers are not equipped with the relevant set of knowledge and skills to consciously foster studentsâ moral development; neither teacher training nor teaching experience appear to influence the teachersâ belief development. However, teachers and trainee teachers are willing and interested both to engage with moral education, and to receive training relevant to conducting moral education. Key findings regarding teachersâ beliefs and attitudes concerning conducting moral education include an inclination towards providing pupils with a scaffold to foster moral development, rather than dogmatic imposition of a certain set of values and virtues; and an inclination towards creating a pluralistic moral environment in the school that fosters compassion and cooperation. Based on the understandings gained from the reviewed literature and analysed data, recommendations are made regarding how to improve ITE programmes with respect to preparing teachers to engage with moral education
Modelling a socialised chatbot using trust development in children: Lessons learnt from Tay
In 2016 Microsoft released Tay.ai to the Twittersphere, a conversational chatbot that was intended to act like a millennial girl. However, they ended up taking Tay's account down in less than 24Â h because Tay had learnt to tweet racist and sexist statements from its online interactions. Taking inspiration from the theory of morality as cooperation, and the place of trust in the developmental psychology of socialisation, we offer a multidisciplinary and pragmatic approach to build on the lessons learnt from Tay's experiences, to create a chatbot that is more selective in its learning, and thus resistant to becoming immoral the way Tay did
HerMES: the rest-frame UV emission and a lensing model for the z= 6.34 luminous dusty starburst galaxy HFLS3
We discuss the rest-frame ultraviolet emission from the starbursting galaxy HFLS3 at a redshift of 6.34. The galaxy was discovered in Herschel/SPIRE data due to its red color in the submillimeter wavelengths from 250 to 500 ÎŒm. Keck/NIRC2 K s -band adaptive optics imaging data showed two potential near-IR counterparts near HFLS3. Previously, the northern galaxy was taken to be in the foreground at z = 2.1, while the southern galaxy was assumed to be HFLS3's near-IR counterpart. The recently acquired Hubble/WFC3 and Advanced Camera for Surveys (ACS) imaging data show conclusively that both optically bright galaxies are in the foreground at z < 6. A new lensing model based on the Hubble imaging data and the millimeter-wave continuum emission yields a magnification factor of 2.2 ± 0.3, with a 95% confidence upper limit on the magnification of 3.5. When corrected for lensing, the instantaneous star formation rate is 1320 M â yrâ1, with the 95% confidence lower limit around 830 M â yrâ1. The dust and stellar masses of HFLS3 from the same spectral energy distribution (SED) models are at the level of 3 Ă 108 M â and ~5 Ă 1010 M â, respectively, with large systematic uncertainties on assumptions related to the SED model. With Hubble/WFC3 images, we also find diffuse near-IR emission about 0.5 arcsec (~3 kpc) to the southwest of HFLS3 that remains undetected in the ACS imaging data. The emission has a photometric redshift consistent with either z ~ 6 or a dusty galaxy template at z ~ 2
Astrobites as a Community-led Model for Education, Science Communication, and Accessibility in Astrophysics
Support for early career astronomers who are just beginning to explore
astronomy research is imperative to increase retention of diverse practitioners
in the field. Since 2010, Astrobites has played an instrumental role in
engaging members of the community -- particularly undergraduate and graduate
students -- in research. In this white paper, the Astrobites collaboration
outlines our multi-faceted online education platform that both eases the
transition into astronomy research and promotes inclusive professional
development opportunities. We additionally offer recommendations for how the
astronomy community can reduce barriers to entry to astronomy research in the
coming decade
Mid-Infrared Spectroscopy of Optically Faint Extragalactic 70 micron Sources
We present mid-infrared spectra of sixteen optically faint sources with 70
micron fluxes in the range 19-38mJy. The sample spans a redshift range of
0.35<z<1.9, with most lying between 0.8<z<1.6, and has infrared luminosities of
10^{12} - 10^{13} solar luminosities. Ten of 16 objects show prominent
polycyclic aromatic hydrocarbon (PAH) emission features; four of 16 show weak
PAHs and strong silicate absorption, and two objects have no discernable
spectral features. Compared to samples with 24 micron fluxes >10mJy, the 70\um
sample has steeper IR continua and higher luminosities. The PAH dominated
sources are among the brightest starbursts seen at any redshift, and reside in
a redshift range where other selection methods turn up relatively few sources.
The absorbed sources are at higher redshifts and have higher luminosities than
the PAH dominated sources, and may show weaker luminosity evolution. We
conclude that a 70 micron selection extending to ~20mJy, in combination with
selections at mid-IR and far-IR wavelengths, is necessary to obtain a complete
picture of the evolution of IR-luminous galaxies over 0<z<2.Comment: ApJ accepte
Environment of the submillimeter-bright massive starburst HFLS3 at 6.34
We describe the search for Lyman-break galaxies (LBGs) near the
sub-millimeter bright starburst galaxy HFLS3 at 6.34 and a study on the
environment of this massive galaxy during the end of reionization.We performed
two independent selections of LBGs on images obtained with the \textit{Gran
Telescopio Canarias} (GTC) and the \textit{Hubble Space Telescope} (HST) by
combining non-detections in bands blueward of the Lyman-break and color
selection. A total of 10 objects fulfilling the LBG selection criteria at
5.5 were selected over the 4.54 and 55.5 arcmin covered by our HST
and GTC images, respectively. The photometric redshift, UV luminosity, and the
star-formation rate of these sources were estimated with models of their
spectral energy distribution. These 6 candidates have physical
properties and number densities in agreement with previous results. The UV
luminosity function at 6 and a Voronoi tessellation analysis of this
field shows no strong evidence for an overdensity of relatively bright objects
(m25.9) associated with \textit{HFLS3}. However, the over-density
parameter deduced from this field and the surface density of objects can not
excluded definitively the LBG over-density hypothesis. Moreover we identified
three faint objects at less than three arcseconds from \textit{HFLS3} with
color consistent with those expected for 6 galaxies. Deeper data are
needed to confirm their redshifts and to study their association with
\textit{HFLS3} and the galaxy merger that may be responsible for the massive
starburst.Comment: 14 pages, 12 figures, accepted for publication in Ap
A population of z> 2 far-infrared Herschel-spire-selected starbursts
We present spectroscopic observations for a sample of 36 Herschel-SPIRE
250-500um selected galaxies (HSGs) at 2<z<5 from the Herschel Multi-tiered
Extragalactic Survey (HerMES). Redshifts are confirmed as part of a large
redshift survey of Herschel-SPIRE-selected sources covering ~0.93deg^2 in six
extragalactic legacy fields. Observations were taken with the Keck I Low
Resolution Imaging Spectrometer (LRIS) and the Keck II DEep Imaging
Multi-Object Spectrograph (DEIMOS). Precise astrometry, needed for
spectroscopic follow-up, is determined by identification of counterparts at
24um or 1.4GHz using a cross-identification likelihood matching method.
Individual source luminosities range from log(L_IR/Lsun)=12.5-13.6
(corresponding to star formation rates 500-9000Msun/yr, assuming a Salpeter
IMF), constituting some of the most intrinsically luminous, distant infrared
galaxies yet discovered. We present both individual and composite rest-frame
ultraviolet spectra and infrared spectral energy distributions (SEDs). The
selection of these HSGs is reproducible and well characterized across large
areas of sky in contrast to most z>2 HyLIRGs in the literature which are
detected serendipitously or via tailored surveys searching only for high-z
HyLIRGs; therefore, we can place lower limits on the contribution of HSGs to
the cosmic star formation rate density at (7+-2)x10^(-3)Msun/yr h^3Mpc^(-3) at
z~2.5, which is >10% of the estimated total star formation rate density (SFRD)
of the Universe from optical surveys. The contribution at z~4 has a lower limit
of 3x10^(-3)Msun/yr h^3 Mpc^(-3), ~>20% of the estimated total SFRD. This
highlights the importance of extremely infrared-luminous galaxies with high
star formation rates to the build-up of stellar mass, even at the earliest
epochs.Comment: 25 pages, 10 figures; ApJ accepte
The Environments of Local Luminous Infrared Galaxies: Star Formation Rates increase with Density
This work studies the environments and star formation relationships of local
luminous infrared galaxies (LIRG) in comparison to other types of local and
distant (z~1) galaxies. The infrared (IR) galaxies are drawn from the IRAS
sample. The density of the environment is quantified using 6dF and Point Source
Catalogue redshift survey (PSCz) galaxies in a cylinder of 2h^-1 Mpc radius and
10h^-1 Mpc length. Our most important result shows the existence of a dramatic
density difference between local LIRGs and local non-LIRG IR galaxies. LIRGs
live in denser environments than non-LIRG IR galaxies implying that L_IR=10^11
h^-2 L_sun marks an important transition point among IR-selected local
galaxies. We also find that there is a strong correlation between the densities
around LIRGs and their L_IR luminosity, while the IR-activity of non-LIRG IR
galaxies does not show any dependence on environment. This trend is independent
of mass-bin selection. The SF-density trend in local LIRGs is similar to that
found in some studies of blue cloud galaxies at z~1 which show a correlation
between star formation and local density (the reversal of the relation seen for
local galaxies). This, together with the rapid decline of the number count of
LIRGs since z~1, could mean that local LIRGs are survivors of whatever process
transformed blue cloud galaxies at z~1 to the present day or local LIRGs came
into existence by similar process than high redshift LIRGs but at later stage.Comment: 13 pages with 6 figures. Discussion expanded and references added to
match accepted MNRAS version, results unchange
Very Strong Emission-Line Galaxies in the WISP Survey and Implications for High-Redshift Galaxies
The WFC3 Infrared Spectroscopic Parallel Survey (WISP) uses the Hubble Space
Telescope (HST) infrared grism capabilities to obtain slitless spectra of
thousands of galaxies over a wide redshift range including the peak of star
formation history of the Universe. We select a population of very strong
emission-line galaxies with rest-frame equivalent widths higher than 200 A. A
total of 176 objects are found over the redshift range 0.35 < z < 2.3 in the
180 arcmin^2 area we analyzed so far. After estimating the AGN fraction in the
sample, we show that this population consists of young and low-mass starbursts
with higher specific star formation rates than normal star-forming galaxies at
any redshift. After spectroscopic follow-up of one of these galaxies with
Keck/LRIS, we report the detection at z = 0.7 of an extremely metal-poor galaxy
with 12+Log(O/H)= 7.47 +- 0.11. The nebular emission-lines can substantially
affect the broadband flux density with a median brightening of 0.3 mag, with
examples producing brightening of up to 1 mag. The presence of strong emission
lines in low-z galaxies can mimic the color-selection criteria used in the z ~
8 dropout surveys. In order to effectively remove low redshift interlopers,
deep optical imaging is needed, at least 1 mag deeper than the bands in which
the objects are detected. Finally, we empirically demonstrate that strong
nebular lines can lead to an overestimation of the mass and the age of galaxies
derived from fitting of their SED. Without removing emission lines, the age and
the stellar mass estimates are overestimated by a factor of 2 on average and up
to a factor of 10 for the high-EW galaxies. Therefore the contribution of
emission lines should be systematically taken into account in SED fitting of
star-forming galaxies at all redshifts.Comment: Accepted for publication in the Astrophysical Journal. 15 pages, 13
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