86 research outputs found
ANALISIS KEPUTUSAN PEMBELIAN DI TOKOPEDIA YANG DIPENGARUHI CELEBRITY ENDORSER, BRAND IMAGE, KELOMPOK REFERENSI DAN USIA
With higher dynamics of lifr makes people want everything quick and instant. It resulted with companies now starting to do e-commerce. The purpose of this research are to find out (1) celebrity endorser influence on purchasing decision in Tokopedia (2) brand image influence on purchasing decision in Tokopedia (3) reference group influence on purchasing decision in Tokopedia (4) age influence on purchasing decision in Tokopedia (5) celebrity endorser, brand image, reference group and age influences on purchasing decision in Tokopedia. Data were analyzed using Logistic Regression. The results of this research are (1) there is no significance influence between celebrity endorser and purchasing decision in Tokopedia. This is indicated by significant value 0.588 greater than 0.05 (2) ) there is significance influence between brand image and purchasing decision in Tokopedia. This is indicated by significant value 0.003 smaller than 0.05 (3) there is significance influence between reference group and purchasing decision in Tokopedia. This is indicated by significant value 0.000 smaller than 0.05 (4) there is no significance influence between age and purchasing decision in Tokopedia. This is indicated by significant value 0.186 greater than 0.05 (5) celebrity endorser, brand image, reference group and age together affect on purchasing decision in Tokopedia of 71.2
ANALISIS KEPUTUSAN PEMBELIAN DI TOKOPEDIA YANG DIPENGARUHI CELEBRITY ENDORSER, BRAND IMAGE, KELOMPOK REFERENSI DAN USIA
With higher dynamics of lifr makes people want everything quick and instant. It resulted with companies now starting to do e-commerce. The purpose of this research are to find out (1) celebrity endorser influence on purchasing decision in Tokopedia (2) brand image influence on purchasing decision in Tokopedia (3) reference group influence on purchasing decision in Tokopedia (4) age influence on purchasing decision in Tokopedia (5) celebrity endorser, brand image, reference group and age influences on purchasing decision in Tokopedia. Data were analyzed using Logistic Regression. The results of this research are (1) there is no significance influence between celebrity endorser and purchasing decision in Tokopedia. This is indicated by significant value 0.588 greater than 0.05 (2) ) there is significance influence between brand image and purchasing decision in Tokopedia. This is indicated by significant value 0.003 smaller than 0.05 (3) there is significance influence between reference group and purchasing decision in Tokopedia. This is indicated by significant value 0.000 smaller than 0.05 (4) there is no significance influence between age and purchasing decision in Tokopedia. This is indicated by significant value 0.186 greater than 0.05 (5) celebrity endorser, brand image, reference group and age together affect on purchasing decision in Tokopedia of 71.2
The far-infrared/radio correlation for a sample of strongly lensed dusty star-forming galaxies detected by Herschel
We investigate the radio/far-infrared (FIR) correlation for a sample of 28 bright high-redshift (1 z 4) star-forming galaxies selected in the FIR from the Herschel -ATLAS fields as candidates to be strongly gravitationally lensed. The radio information comes either from high sensitivity dedicated Australia Telescope Compact Array observations at 2.1 GHz or from cross-matches with the FIRST surv e y at 1.4 GHz. By taking advantage of source brightness possibly enhanced by lensing magnification, we identify a weak evolution with redshift out to z 4 of the FIR-to-radio luminosity ratio q FIR . We also find that the q FIR parameter as a function of the radio power L 1 . 4 GHz displays a clear decreasing trend, similarly to what is observed for optically/radio- selected lensed quasars found in literature, yet co v ering a complementary region in the q FIR âL 1 . 4 GHz diagram. We interpret such a behaviour in the framework of an in situ galaxy formation scenario, as a result of the transition from an early dust-obscured star-forming phase (mainly pinpointed by our FIR selection) to a late radio-loud quasar phase (preferentially sampled by the optical/radio selection)
A titanic interstellar medium ejection from a massive starburst galaxy at redshift 1.4
Feedback-driven winds from star formation or active galactic nuclei might be a relevant channel for the abrupt quenching of star formation in massive galaxies. However, both observations and simulations support the idea that these processes are non-conflictingly co-evolving and self-regulating. Furthermore, evidence of disruptive events that are capable of fast quenching is rare, and constraints on their statistical prevalence are lacking. Here we present a massive starburst galaxy at redshift z = 1.4, which is ejecting 46 ± 13% of its molecular gas mass at a startling rate of âł10,000 Mâ yrâ1. A broad component that is red-shifted from the galaxy emission is detected in four (low and high J) CO and [C i] transitions and in the ionized phase, which ensures a robust estimate of the expelled gas mass. The implied statistics suggest that similar events are potentially a major star-formation quenching channel. However, our observations provide compelling evidence that this is not a feedback-driven wind, but rather material from a merger that has been probably tidally ejected. This finding challenges some literature studies in which the role of feedback-driven winds might be overstated
Illuminating the Dark Side of Cosmic Star Formation II. A second date with RS-NIRdark galaxies in COSMOS
About 12 billion years ago, the Universe was first experiencing light again
after the dark ages, and galaxies filled the environment with stars, metals and
dust. How efficient was this process? How fast did these primordial galaxies
form stars and dust? We can answer these questions by tracing the Star
Formation Rate Density (SFRD) back to its widely unknown high redshift tail,
traditionally observed in the Near-InfraRed (NIR), Optical and UV bands. Thus,
the objects with a high amount of dust were missing. We aim to fill this
knowledge gap by studying Radio Selected NIR-dark (\textit{RS-NIRdark})
sources, i.e. sources not having a counterpart at UV-to-NIR wavelengths. We
widen the sample by Talia et al. (2021) from 197 to 272 objects in the COSMic
evolution Survey (COSMOS) field, including also photometrically contaminated
sources, previously excluded. Another important step forward consists in the
visual inspection of each source in the bands from u* to MIPS-24m.
According to their "environment" in the different bands, we are able to
highlight different cases of study and calibrate an appropriate photometric
procedure for the objects affected by confusion issues. We estimate that the
contribution of RS-NIRdark to the Cosmic SFRD at 3z5 is 10--25
of that based on UV-selected galaxies
ALPINEâALMA [CâII] Survey: on the nature of an extremely obscured serendipitous galaxy
We report the serendipitous discovery of a dust-obscured galaxy observed as part of the Atacama Large Millimeter Array (ALMA) Large Program to INvestigate [CâII] at Early times (ALPINE). While this galaxy is detected both in line and continuum emissions in ALMA Band 7, it is completely dark in the observed optical/near-infrared bands and only shows a significant detection in the UltraVISTA K_s band. We discuss the nature of the observed ALMA line, that is [CâII] at z ⌠4.6 or high-J CO transitions at z ⌠2.2. In the first case, we find a [CâII]/FIR luminosity ratio of log(L_([CII])/L_(FIR))âŒâ2.5â , consistent with the average value for local star-forming galaxies (SFGs). In the second case instead, the source would lie at larger CO luminosities than those expected for local SFGs and high-z submillimetre galaxies. At both redshifts, we derive the star formation rate (SFR) from the ALMA continuum and the physical parameters of the galaxy, such as the stellar mass (M*), by fitting its spectral energy distribution. Exploiting the results of this work, we believe that our source is a âmain-sequenceâ, dusty SFG at z = 4.6 (i.e. [CâII] emitter) with log(SFR/M_â yrâ»Âč) ⌠1.4 and log(M*/M_â) ⌠9.9. As a support to this scenario our galaxy, if at this redshift, lies in a massive protocluster recently discovered at z ⌠4.57, at only âŒ1 proper Mpc from its centre. This work underlines the crucial role of the ALPINE survey in making a census of this class of objects, in order to unveil their contribution to the global SFR density at the end of the Reionization epoch
The ALPINE-ALMA [CII] Survey: On the nature of an extremely obscured serendipitous galaxy
We report the serendipitous discovery of a bright galaxy (Gal-A) observed as
part of the ALMA Large Program to INvestigate [CII] at Early times (ALPINE).
While this galaxy is detected both in line and continuum emission in ALMA Band
7, it is completely dark in UV/optical filters and only presents a marginal
detection in the UltraVISTA Ks band. We discuss the nature of the observed ALMA
line, i.e. whether the emission comes from [CII] at z~4.6, or from high-J CO
transitions at z~2.2. In the first case we find a [CII]-to-FIR luminosity ratio
of log(L_[CII]/L_FIR)=-2.5, consistent with the average value for local
star-forming galaxies (SFGs); in the second case, instead, the source would lie
outside of the empirical relations between L_CO and L_FIR found in the
literature. At both redshifts, we derive the star-formation rate (SFR) from the
ALMA continuum, and the stellar mass (M*) by using stellar population synthesis
models as input for LePHARE spectral energy distribution (SED) fitting.
Exploiting our results, we believe that Gal-A is a Main-Sequence (MS), dusty
SFG at z=4.6 (i.e. [CII] emitter) with log(SFR/[M/yr])~1.4 and log(M*/M)~9.7.
This work underlines the crucial role of the ALPINE survey in making a census
of this class of objects, in order to unveil their contribution to the global
star-formation rate density (SFRD) of the Universe at the end of the
Reionisation epoch.Comment: 13 pages, 6 figures. Submitted to MNRA
Chandra and ALMA observations of the nuclear activity in two strongly lensed star-forming galaxies
Aim. According to coevolutionary scenarios, nuclear activity and star formation play relevant roles in the early stages of galaxy formation. We aim at identifying them in high-redshift galaxies by exploiting high-resolution and high-sensitivity X-ray and millimeter-wavelength data to confirm the presence or absence of star formation and nuclear activity and describe their relative roles in shaping the spectral energy distributions and in contributing to the energy budgets of the galaxies. Methods. We present the data, model, and analysis in the X-ray and millimeter (mm) bands for two strongly lensed galaxies, SDP.9 (HATLAS J090740.0-004200) and SDP.11 (HATLAS J091043.1-000322), which we selected in the Herschel-ATLAS catalogs for their excess emission in the mid-IR regime at redshift b3 1.5. This emission suggests nuclear activity in the early stages of galaxy formation. We observed both of them with Chandra ACIS-S in the X-ray regime and analyzed the high-resolution mm data that are available in the ALMA Science Archive for SDP.9. By combining the information available in mm, optical, and X-ray bands, we reconstructed the source morphology. Results. Both targets were detected in the X-ray, which strongly indicates highly obscured nuclear activity. ALMA observations for SDP.9 for the continuum and CO(6-5) spectral line with high resolution (0.02 arcsec corresponding to 3c65 pc at the distance of the galaxy) allowed us to estimate the lensed galaxy redshift to a better accuracy than pre-ALMA estimates (1.5753 \ub1 0.0003) and to model the emission of the optical, millimetric, and X-ray band for this galaxy. We demonstrate that the X-ray emission is generated in the nuclear environment, which strongly supports that this object has nuclear activity. On the basis of the X-ray data, we attempt an estimate of the black hole properties in these galaxies. Conclusions. By taking advantage of the lensing magnification, we identify weak nuclear activity associated with high-z galaxies with high star formation rates. This is useful to extend the investigation of the relationship between star formation and nuclear activity to two intrinsically less luminous high-z star-forming galaxies than was possible so far. Given our results for only two objects, they alone cannot constrain the evolutionary models, but provide us with interesting hints and set an observational path toward addressing the role of star formation and nuclear activity in forming galaxies
Bright Extragalactic ALMA Redshift Survey (BEARS) III: Detailed study of emission lines from 71 Herschel targets
We analyse the molecular and atomic emission lines of 71 bright
Herschel-selected galaxies between redshifts 1.4 to 4.6 detected by the Atacama
Large Millimetre/submillimetre Array. These lines include a total of 156 CO, [C
I], and H2O emission lines. For 46 galaxies, we detect two transitions of CO
lines, and for these galaxies we find gas properties similar to those of other
dusty star-forming galaxy (DSFG) samples. A comparison to photo-dissociation
models suggests that most of Herschel-selected galaxies have similar
interstellar medium conditions as local infrared-luminous galaxies and
high-redshift DSFGs, although with denser gas and more intense far-ultraviolet
radiation fields than normal star-forming galaxies. The line luminosities agree
with the luminosity scaling relations across five orders of magnitude, although
the star-formation and gas surface density distributions (i.e.,
Schmidt-Kennicutt relation) suggest a different star-formation phase in our
galaxies (and other DSFGs) compared to local and low-redshift gas-rich, normal
star-forming systems. The gas-to-dust ratios of these galaxies are similar to
Milky Way values, with no apparent redshift evolution. Four of 46 sources
appear to have CO line ratios in excess of the expected maximum (thermalized)
profile, suggesting a rare phase in the evolution of DSFGs. Finally, we create
a deep stacked spectrum over a wide rest-frame frequency (220-890 GHz) that
reveals faint transitions from HCN and CH, in line with previous stacking
experiments.Comment: 30 pages, 17 figures, accepted for publication in Monthly Notices of
the Royal Astronomical Society Main Journal. Comments are warmly welcome
A longitudinal study investigating quality of life and nutritional outcomes in advanced cancer patients receiving home parenteral nutrition
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