Study of star formation rate and metallicity of the low redshift (z < 0.02) dwarf galaxies

BIBECHANA ◽  
2021 ◽  
Vol 18 (2) ◽  
pp. 43-49
Author(s):  
S. P. Gautam ◽  
A. Silwal ◽  
N. Lamichhane ◽  
A. K. Jha ◽  
B. Aryal
Keyword(s):  
Star Formation ◽  
Full Width Half Maximum ◽  
Dwarf Galaxies ◽  
Star Formation Rate ◽  
Regression Coefficient ◽  
Formation Rate ◽  
Emission Lines ◽  
Full Width ◽  
Gaussian Fit ◽  
Low Rate

In this paper, we have presented an analysis of emission lines from two dwarf galaxies. We analyzed the strongest emission lines of wavelength ranging from 4100 Å to 6700 Å.  Among these emission lines, Hα and OIII have the highest intensities with 113.09×10-17 erg/s/cm2/Å and 142.12×10-17 erg/s/cm2/Å in the galaxies SDSSJ222726.64+120539.8 and SDSSJ162753.47+482529.3, respectively. The Gaussian fit carried out in these emission lines showed the perfect fits with regression coefficient greater than 98 %, and full width half maximum (FWHM) of less than 4 Å. The line ratios calculated between Hα and Hβ for SDSSJ222726.64+120539.8 and SDSSJ162753.47+482529.3 were 2.78 and 2.85, respectively, suggesting that the galaxies are starburst galaxies. The measurement of the Hα line from both galaxies was then used to assess the rate of star formation. The star formation rate of the galaxies SDSSJ222726.64+120539.8 and SDSSJ162753.47+482529.3 was found to be 0.010 M☉year-1 and 0.016 M☉year-1, respectively, indicating a low rate of star formation, and the emission line metallicity was derived using the Hα and NII line, which were measured to be 8.23 dex and 8.70 dex, respectively. BIBECHANA 18 (2) (2021) 43-49

scholarly journals THE GAS PHASE MASS METALLICITY RELATION FOR DWARF GALAXIES: DEPENDENCE ON STAR FORMATION RATE AND HI GAS MASS

2015 ◽  
Vol 812 (2) ◽  
pp. 98 ◽  
Author(s):  
Jimmy ◽  
Kim-Vy Tran ◽  
Amélie Saintonge ◽  
Gioacchino Accurso ◽  
Sarah Brough ◽  
...  
Keyword(s):  
Star Formation ◽  
Gas Phase ◽  
Dwarf Galaxies ◽  
Star Formation Rate ◽  
Formation Rate

scholarly journals A spectroscopic measure of the star formation rate density in dwarf galaxies atz∼ 1

2009 ◽  
Vol 395 (1) ◽  
pp. L76-L80 ◽  
Author(s):  
G. T. Davies ◽  
David G. Gilbank ◽  
Karl Glazebrook ◽  
Richard G. Bower ◽  
I. K. Baldry ◽  
...  
Keyword(s):  
Star Formation ◽  
Dwarf Galaxies ◽  
Star Formation Rate ◽  
Formation Rate

scholarly journals Study of Star Formation Rate and Metallicity of an Interacting Dwarf Galaxy NGC 2604

2020 ◽  
Vol 25 (2) ◽  
pp. 55-60
Author(s):  
Daya Nidhi Chhatkuli ◽  
Sanjaya Paudel ◽  
Binil Aryal
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Dwarf Galaxy ◽  
Formation Rate ◽  
Emission Lines ◽  
A Value ◽  
Characteristic Emission ◽  
Characteristic Lines ◽  
The Galaxy ◽  
Hα Emission

We present a study of the Sloan Digital all Sky Survey Data Release 12 (SDSS DR12) optical spectra of an interacting dwarf galaxy NGC 2604 that has redshift 0.0069. Thirteen characteristic emission lines were identified in the wavelength range of 3885 Å to 6742 Å, the strongest line was due to Hα emission with a value of emission-line flux 1538.8 erg/s/cm2/Å. The other twelve emission lines were observed because of OI doublet, Hβ, Hγ, Hδ, OIII doublet, HeI, SII doublet and NII doublet transitions. Eleven characteristic lines agreed perfectly with the Gaussian distribution with greater than 99.9 % coefficient of regression. However, full-width half maximum (FWHM) was found to be less than 5 Å. No absorption metallic lines were observed in the spectra which indicates that the galaxy was either newly formed. The line metallicity of the galaxy was found to be 8.4 dex and the extinction coefficient was 0.2134. The star formation rate due to Hα emission after extinction correction was found to be 0.0927 Mʘ year -1 which is almost double of the value (0.057 Mʘ year -1) before correction.

scholarly journals The OTELO survey

2019 ◽  
Vol 631 ◽  
pp. A10 ◽  
Author(s):  
Marina Ramón-Pérez ◽  
Ángel Bongiovanni ◽  
Ana María Pérez García ◽  
Jordi Cepa ◽  
Maritza A. Lara-López ◽  
...  
Keyword(s):  
Star Formation ◽  
Equivalent Width ◽  
Luminosity Function ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Emission Lines ◽  
Different Types

Aims. We take advantage of the capability of the OTELO survey to obtain the Hα luminosity function (LF) at z ∼ 0.40. Because of the deepest coverage of OTELO, we are able to determine the faint end of the LF, and thus better constrain the star formation rate and the number of galaxies at low luminosities. The AGN contribution to this LF is estimated as well. Methods. We make use of the multiwavelength catalogue of objects in the field compiled by the OTELO survey, which is unique in terms of minimum flux and equivalent width. We also take advantage of the pseudo-spectra built for each source, which allow the identification of emission lines and the discrimination of different types of objects. Results. The Hα luminosity function at z ∼ 0.40 is obtained, which extends the current faint end by almost 1 dex, reaching minimal luminosities of log10Llim = 38.5 erg s−1 (or ∼0.002 M⊙ yr−1). The AGN contribution to the total Hα luminosity is estimated. We find that no AGN should be expected below a luminosity of log10L = 38.6 erg s−1. From the sample of non-AGN (presumably, pure SFG) at z ∼ 0.40 we estimated a star formation rate density of ρSFR = 0.012 ± 0.005 M⊙ yr−1 Mpc−3.

Star formation in dwarf galaxies in the ELAIS N1 field

2018 ◽  
Vol 14 (S344) ◽  
pp. 292-295
Author(s):  
Tímea O. Kovács ◽  
Denis Burgarella ◽  
L. Viktor Tóth
Keyword(s):  
Star Formation ◽  
Dwarf Galaxies ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Spectral Energy ◽  
Energy Distributions ◽  
Normal Galaxies ◽  
Radiation Data ◽  
Order Of Magnitude ◽  
Stellar Masses

AbstractWe estimated several parameters of dwarf galaxies, including their star formation rate and dust mass, and compared them with galaxies with larger stellar masses.We have chosen dwarf galaxies in the ELAIS N1 field, and fitted their Spectral Energy Distributions (SED). We used data from the new Herschel SPIRE and PACS Point Source catalogues to constrain the infrared radiation. Data available in VIZIER from multiple surveys have also been used.We determined that the star formation rate (SFR), M* and Mdust is one order of magnitude lower in dwarf galaxies compared to galaxies with larger stellar masses. However, the starburtiness was higher in the dwarf galaxies. They also had lower redshifts than normal galaxies, so we compared them to a subsample of normal galaxies with lower redshifts. The dust masses and SFRs of the dwarf galaxies were slightly lower, but their starburtiness was higher.

scholarly journals Seeking footprints of the primeval Universe in dwarf galaxies

2012 ◽  
Vol 10 (H16) ◽  
pp. 273-274
Author(s):  
Sebastian L. Hidalgo ◽  
Keyword(s):  
Star Formation ◽  
Dwarf Galaxies ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Stellar Content ◽  
Time Intervals ◽  
Fundamental Properties ◽  
Star Formation Histories

AbstractWe present the star formation histories (SFHs) of four isolated dwarf galaxies, Cetus, Tucana, LGS-3, and Phoenix, as a function of galactocentric radius. Our results suggest that beyond some distance from the center, there are no significative differences in fundamental properties of these galaxies, such as the star formation rate (SFR) or age-metallicity relation (AMR). The stellar content of this region would be composed of old (≳ 10.5 Gyr) metal-poor stars only. In the innermost regions, dwarf galaxies appear to have formed stars during time intervals which duration varies from galaxy to galaxy. This extended star formation produces the dichotomy between dwarf spheroidal (dSph) and dwarf Transition (dTr) galaxy types.

scholarly journals Star Formation Rate of the Low Redshift Dwarf Galaxies J080947.50+213717.2 and J151839.94+220514.4

2021 ◽  
Vol 7 (1) ◽  
pp. 18-24
Author(s):  
S. P. Gautam ◽  
A. Silwal ◽  
A. Sedain ◽  
B. Aryal
Keyword(s):  
Star Formation ◽  
Dwarf Galaxies ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Strong Emission ◽  
Star Forming ◽  
Normal Galaxies ◽  
Characteristic Lines ◽  
Low Surface Brightness ◽  
Low Surface Brightness Galaxies

We performed a spectroscopic analysis of two low redshift dwarf galaxies, SDSSJ080947.50+213717.2, and SDSSJ151839.94+220514.4 selected from a catalogue of Paudel et al. 2018. The strong emission lines of the SDSS spectra of both galaxies were studied and the elements responsible were identified for those characteristic lines. The line ratio between Hα and Hβ (Hα/ Hβ) for the galaxies SDSSJ080947.50+213717.2 and SDSSJ151839.94+220514.4 was found to be 2.77 and 2.75, respectively, suggesting these are nearly dust free and star forming galaxies.. The star formation rate of the galaxies SDSSJ080947.50+213717.2 and SDSSJ151839.94+220514.4 was found to be 0.0232 M☉yr-1 and 0.05221 M☉yr-1, respectively. The ratio between NII and Hα was used to calculate the emission line metallicity, which was found to be 8.13 dex and 8.46 dex for the galaxies SDSSJ080947.50+213717.2 and SDSSJ151839.94+220514.4, respectively. From the comparison of our findings with the previous studies, slightly lower star formation rate than normal galaxies were noticed. The metallicity value for both of the galaxies were positioned in the group of low-surface-brightness galaxies of Bargvell's dwarfs..

scholarly journals Evolution of Dwarf Galaxies in the Centaurus A Group

2007 ◽  
Vol 3 (S244) ◽  
pp. 326-330 ◽  
Author(s):  
L. Makarova ◽  
D. Makarov
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Dwarf Galaxies ◽  
Star Formation Rate ◽  
Formation Rate ◽  
The Galaxy ◽  
Probable Origin ◽  
Centaurus A ◽  
Environmental Dependence

AbstractWe consider the star formation properties of dwarf galaxies in the Cen A group observed within our HST/ACS projects number 9771 and 10235. We model color-magnitude diagrams of the galaxies under consideration and measure star formation rate and metallicity dependence on time. We study the environmental dependence of the galaxy evolution and probable origin of the dwarf galaxies in the group.

scholarly journals SLOW EVOLUTION OF THE SPECIFIC STAR FORMATION RATE ATz> 2: THE IMPACT OF DUST, EMISSION LINES, AND A RISING STAR FORMATION HISTORY

2014 ◽  
Vol 781 (1) ◽  
pp. 34 ◽  
Author(s):  
Valentino González ◽  
Rychard Bouwens ◽  
Garth Illingworth ◽  
Ivo Labbé ◽  
Pascal Oesch ◽  
...  
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Dust Emission ◽  
Emission Lines ◽  
Star Formation History ◽  
Formation History ◽  
Slow Evolution ◽  
The Impact

scholarly journals Enhanced X-ray emission from candidate Lyman continuum emitting galaxies

2019 ◽  
Vol 487 (3) ◽  
pp. 4093-4101 ◽  
Author(s):  
J Bluem ◽  
P Kaaret ◽  
A Prestwich ◽  
M Brorby
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Emission Lines ◽  
X Rays ◽  
Blue Colour ◽  
X Ray ◽  
Near Ultraviolet ◽  
Lyman Continuum ◽  
X Ray Binaries

ABSTRACT X-ray binaries may have helped reionize the early Universe by enabling Lyman continuum escape. We analysed a set of eight local galaxies that are potential Lyman leaking galaxies, identified by a blue colour and weak emission lines, using Chandra X-ray observations. Five of the galaxies feature X-ray sources, while three galaxies are not significantly detected in X-rays. X-ray luminosities were found for the galaxies and X-ray sources. Four of the galaxies have elevated X-ray luminosity versus what would be expected based on star formation rate and metallicity. The presence of detected X-ray sources within the galaxies is found to correlate with the ratio of the star formation rate estimated from the near-ultraviolet flux to that estimated from the infrared. This implies reduced obscuration due to dust in the galaxies with X-ray sources. These results support the idea that X-ray binaries may be an important part of the process of reionziation.

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