SFR Values Research Articles

MIDIS: The Relation between Strong (Hβ + [O iii]) Emission, Star Formation, and Burstiness around the Epoch of Reionization

We investigate the properties of strong (Hβ + [O iii]) emitters before and after the end of the “Epoch of Reionization” from z = 8 to z = 5.5. We make use of ultradeep JWST/NIRCam imaging in the parallel field (P2) of the MIRI Deep Imaging Survey (MIDIS) in the Hubble eXtreme Deep Field (H-XDF), in order to select prominent (Hβ + [O iii]) emitters (with rest-frame equivalent width (EW0) ≳ 100 Å) at z = 5.5–7, based on their flux density enhancement in the F356W band with respect to the spectral energy distribution continuum. We complement our selection with other (Hβ + [O iii]) emitters from the literature at similar and higher (z = 7−8) redshifts. We find (nonindependent) anticorrelations between EW0(Hβ + [O iii]) and both galaxy stellar mass and age, in agreement with previous studies, and a positive correlation with specific star formation rate (sSFR). On the SFR–M ⋆ plane, the (Hβ + [O iii]) emitters populate both the star formation main sequence and the starburst region, which become indistinguishable at low stellar masses ( log10(M⋆)<7.5 ). We find tentative evidence for a nonmonotonic relation between EW0(Hβ + [O iii]) and SFR, such that both parameters correlate with each other at SFR ≳ 1 M ⊙ yr−1, while the correlation flattens out at lower SFRs. This suggests that low metallicities producing high EW0(Hβ + [O iii]) could be important at low SFR values. Interestingly, the properties of the strong emitters and other galaxies (33% and 67% of our z = 5.5–7 sample, respectively) are similar, including, in many cases, high sSFR. Therefore, it is crucial to consider both emitters and nonemitters to obtain a complete picture of the cosmic star formation activity around the Epoch of Reionization.

Analysis on the innovative education mode of the integration of information technology and traditional teaching in the era of big data

Abstract In order to develop students’ concentration in the classroom, this paper proposes to analyze students’ learning concentration from three dimensions, where the superiority of the random forest classification algorithm is found in the dimension of head posture estimation so that students’ attention ranges can be analyzed. For data acquisition, the OpenPose platform is used for real-time detection of body, foot, hand, and face key points. A comprehensive evaluation study of students’ concentration levels in the classroom was achieved through an effective algorithm. Finally, the multimodal information fusion algorithm was investigated, and it was concluded that the weights could be calculated by hierarchical analysis to achieve a comprehensive evaluation of students’ learning concentration. By analyzing the course data of 12 students, the distribution of SFR values, Yaw angle and Pitch angle distribution, PERCLOS value distribution, and correct/error rate distribution of answers were counted, and the final scores of respective learning engagement were obtained as 0.91, 0.62, 0.80, 0.36, 0.82, 0.73, 0.81, 0.63, 0.81, 0.81 The model scores were compared with the expert scores, and the accuracy rate reached 98.6%, which proved that the model proposed in this paper is effective and can correctly reflect the real state of students’ learning in the classroom.

UVIT view of NGC 5291: Ongoing star formation in tidal dwarf galaxies at ∼ 0.35 kpc resolution

ABSTRACT NGC 5291, an early-type galaxy surrounded by a giant H i ring, is believed to be formed from collision with another galaxy. Several star forming complexes and tidal dwarf galaxies are distributed along the collisional ring which are sites of star formation in environments where extreme dynamical effects are involved. Dynamical effects can affect the star formation properties and the spatial distribution of star forming complexes along the tidal features. To study and quantify the star formation activity in the main body and in the ring structure of the NGC 5291 system, we use high spatial resolution FUV and NUV imaging observations from the Ultraviolet Imaging Telescope onboard AstroSat. A total of 57 star-forming knots are identified to be part of this interacting system out of which 12 are new detections (star forming complexes that lie inside the H i contour) compared to the previous measurements from lower resolution UV imaging. We estimate the attenuation in UV for each of the resolved star-forming knots using the UV spectral slope β, derived from the FUV − NUV colour. Using the extinction corrected UV fluxes, we derive the star formation rate of the resolved star forming complexes. The extinction corrected total star formation rate of this system is estimated as 1.75 ± 0.04 $\mathrm{M_\odot \, yr}^{-1}$. The comparison with dwarf galaxy populations (BCD, Sm, and dIm galaxies) in the nearby Universe shows that many of the knots in the NGC 5291 system have SFR values comparable to the SFR of BCD galaxies.

The Effect of colliding galaxies on star formation rates based on IllustrisTNG

Galaxy collisions are a complex and common cosmic phenomenon that attracts attention of plenty of scholars. In this paper, the effect of colliding galaxies on the star formation rates will be investigated based on IllustrisTNG, considering three properties of colliding galaxies: distance, velocity and mass. According to the analysis, the deeper the galaxies collide, the larger the SFR values they have. Besides, the effect of collisional and tidal forces on the SFR is continuous. In collisions, galaxies with high relative velocity have higher SFR values compared to galaxies with low velocity; the lighter galaxies have higher SFR values and are more pronounced as the mass ratio of the two galaxies becomes larger. When the colliding galaxies are close in mass, the collision does not have a significant effect on the SFR of both sides. In connection with these results, the possible reasons are discussed for the changing of the SFR by galaxy collisions, i.e., galaxy collisions lead to structural instability of gas clouds in galaxies, causing star formation. These results shed light on guiding further exploration of star formation.

RIRS AND MINI-PCNL IN MANAGEMENT OF KIDNEY STONE: A COMPARATIVE STUDY

To compare results of retrograde intrarenal surgery and minimally invasive percutaneous nephrolithotomy in older patients, a retrospective study was conducted at the Department of Nephrology &amp; Urology of MMDC&amp;Ibn-e-Sina Hospital Multan from January 2021 to January 2022. The study included 135 patients, 65 underwent M-PCNL while 70 underwent RIRS. Gender, age, BMI, ASA scores, stone location and size, ESWL history, SFR and relevant parameters were recorded. Characteristics like gender, age, BMI, stone size and location, HU and ESWL history did not vary significantly in both group (p&gt;0.05). Mean ASA scores and the data of ASA I and ASA II in both groups was also similar (p&gt;0.05). Postoperative Clavien complications, operation time and postoperative transfusion rate in both groups did not vary significantly (p&gt;0.05). M-PCNL patients had greater post operative SFR values (p&lt;0.05). Retrograde intrarenal surgery and minimally invasive percutaneous nephrolithotomy arerecommended methodsin treatment of kidney stones.

Comparison of mini-PCNL and retrograde intrarenal surgery in the treatment of kidney stone over 50 years old patients.

Mini-Percutaneous Nephrolithotomy (M-PCNL) and Retrograde Intrarenal Surgery (RIRS) are commonly used methods in treatment of kidney stones. The aim of our study is to compare the efficacy and safety of M-PCNL and RIRS in kidney stone treatment over 50 years old patients. A total of 125 patients, 65 of whom had RIRS, and 60 of whom had M-PCNL, were included in the study. Age, gender, BMI (Body-Mass Index), ASA (American Society of Anesthesiology) scores of the patients; stone size, stone location, operation side, ESWL history, HU (Hounsfield Unit) values, hospital stay durations, SFR, complication rates according to Clavien modification system, postoperative hemoglobin loss, postoperative transfusion rates, and patients who needed a secondary operation were recorded. SFR values were calculated in the postoperative third and sixth months. The data between the two groups had similar characteristics in terms of age, gender, BMI, HU, stone size, operation side, stone location, ESWL history, operation time, postoperative transfusion rate, postoperative Clavien complications (p > 0.05). When the ASA categories were evaluated, the mean ASA scores, ASA I, and ASA II data had similar characteristics in both groups (p > 0.05). When the ASA 3 scores were evaluated, the number of ASA III patients in the RIRS group was statistically significantly higher (p < 0.05). When hospital stay duration and postoperative hemoglobin loss were examined, RIRS group was found to be advantageous (p < 0.05). Postoperative third month SFR and Postoperative sixth month values were statistically significantly higher in M-PCNL group (p < 0.05). M-PCNL and RIRS are methods that can be used safely and effectively over 50 years old patients in kidney stone surgery. M-PCNL has been found to be more advantageous in terms of SFR rates and as it requires less secondary intervention. RIRS is advantageous in terms of short hospital stay, postoperative hemoglobin loss, and applicability to patients who are not suitable for the prone position.

Dewaterability and degradability of municipal wastewater sludge by electrooxidation/electrocoagulation (EOx/EC) and ultrasound-assisted electrooxidation/electrocoagulation(US/EOx/EC) processes: Determination of operational conditions

In this study, the potential use of electrooxidation-electrocoagulation and ultrasound-assisted electrooxidation-electrocoagulation processes with hybrid electrodes to improve the dewaterability and degradability of active sludge was investigated. Effects of electrode type, current density, electrode connection mode, air injection flow rate, and electrode distance on sludge dewaterability and degradability were determined through measuring specific resistance to filtration (SRF), filtration time (s), degree of degradation (DD, %) and sludge moisture content (Mc, %). To determine the effects of the ultrasound-assisted electrochemical process, experiments were conducted in a different reactor under optimum conditions of the electrochemical process, constant frequency (40 kHz), and varying ultrasound powers (60–240 W). The experiments results showed that for all electrode materials, at high values of current density, the dewaterability of the sludge decreased while the degradability of the sludge increased. Besides, both filtration times and degree of degradation decreased with increasing air injection flow rates. Under the optimum operational conditions (TiPbO2-Fe-SS-SS hybrid electrode type, 100 A/m2 current density, MP-P connection mode, 1 L/min air injection flow rate, 1 cm electrode distance, and 20 min operation time), SRF value decreased from 50 × 1012 m/kg to 2.02 × 1012 m/kg, filtration times decreased from 132 s to 9 s, DD value was observed as 20.2% and Mc value was observed as 42.3%. Under the optimum operational conditions of electrooxidation-electrocoagulation process, sludge DD values in the ultrasound-assisted electrooxidation-electrocoagulation process increased, but SFR values decreased. The structural change in the sludge after each process was determined by SEM analysis.

Evidence for Non-smooth Quenching in Massive Galaxies at z ∼ 1

Abstract We investigate a large sample of massive galaxies at z ∼ 1 with combined HST broad-band and grism observations to constrain the star-formation histories of these systems as they transition from a star-forming state to quiescence. Among our sample of massive ($M_*&gt;10^{10}~\hbox{${\rm M}_{\odot }$}{}$) galaxies at 0.7 &lt; z &lt; 1.2, dust-corrected Hα and UV star-formation indicators agree with a small dispersion (∼0.2 dex) for galaxies on the main sequence, but diverge and exhibit substantial scatter (∼0.7 dex) once they drop significantly below the star-forming main sequence. Significant Hα emission is present in galaxies with low dust-corrected UV SFR values as well as galaxies classified as quiescent using the UVJ diagram. We compare the observed Hα flux distribution to the expected distribution assuming bursty or smooth star-formation histories, and find that massive galaxies at z ∼ 1 are most consistent with a quick, bursty quenching process. This suggests that mechanisms such as feedback, stochastic gas flows, and minor mergers continue to induce low-level bursty star formation in massive galaxies at moderate redshift, even as they quench.

Oxygen saturation/FIO2 ratio at 36 weeks' PMA in 1005 preterm infants: Effect of gestational age and early respiratory disease patterns.

To assess oxygen diffusion at 36 weeks' post-menstrual age in preterm infants by means of the non-invasive oxygen saturation/fraction of inspired oxygen ratio (36w-SFR) and to identify factors associated with 36w-SFR - ie, gestational age (GA) and early respiratory disease patterns (ERP). Retrospective analysis of prospectively collected data. Neonatal Intensive Care Unit. 1005 preterm infants born below 32 weeks' GA. 36w-SFR was the mean of SFR values over 24 h on the day infants reached 36 weeks' PMA. 36w-SFR. descriptive statistics, univariate, and multivariate analysis to study associations of 36w-SFR, including GA and ERP. 36w-SFR was significantly different between infants with and without bronchopulmonary dysplasia (BPD) (371 vs 467, P < 0.001), and according to ERP (LowFIO2 466, pulmonary improvement-PI 460, pulmonary deterioration-PD 405, early persistent pulmonary deterioration-EPPD 344, P < 0.001). Significant differences were found either in BPD and in non-BPD patients according to ERP (P < 0.001). Patients without BPD had significant differences in 36w-SFR according to GA (P < 0.001), while infants with BPD and increasing GA at birth had a non-significant trend for increased 36w-SFR (P = 0.621). Factors associated with 36w-SFR were GA, being small for GA, sepsis, human milk feeding, and ERP. Preterm infants without BPD had a spectrum of oxygen diffusion impairment that was inversely associated with GA at birth. Infants with different patterns of ERP had significant differences in 36w-SFR.

An Estimation of the Star Formation Rate in the Perseus Complex

Abstract We present the results of our investigation of the star-forming potential in the Perseus star-forming complex. We build on previous starless core, protostellar core, and young stellar object (YSO) catalogs from Spitzer (3.6–70 μm), Herschel (70–500 μm), and SCUBA (850 μm) observations in the literature. We place the cores and YSOs within seven star-forming clumps based on column densities greater than cm−2. We calculate the mean density and free-fall time for 69 starless cores as ∼5.55 g cm−3 and ∼0.1 Myr, respectively, and we estimate the star formation rate for the near future as ∼150 M ⊙ Myr−1. According to Bonnor–Ebert stability analysis, we find that majority of starless cores in Perseus are unstable. Broadly, these cores can collapse to form the next generation of stars. We found a relation between starless cores and YSOs, where the numbers of young protostars (Class 0 + Class I) are similar to the numbers of starless cores. This similarity, which shows a one-to-one relation, suggests that these starless cores may form the next generation of stars with approximately the same formation rate as the current generation, as identified by the Class 0 and Class I protostars. It follows that if such a relation between starless cores and any YSO stage exists, the SFR values of these two populations must be nearly constant. In brief, we propose that this one-to-one relation is an important factor in better understanding the star formation process within a cloud.

Proximal optical sensing of cucumber crop N status using chlorophyll fluorescence indices

Sustainable N management of intensive vegetable crops requires accurate and timely on-farm assessment of crop N status. Proximal fluorescence-based sensors are promising tools for monitoring crop N status, by providing non-destructive optical measurements of N-sensitive indicator compounds such as chlorophyll and flavonols. The ability of the Multiplex® fluorescence sensor to determine crop N status was evaluated in two indeterminate cucumber crops grown in contrasting seasons (autumn and spring). Three fluorescence indices, leaf chlorophyll (SFR) and flavonols (FLAV) contents, and their ratio (Nitrogen Balance Index, NBI) were evaluated, and their consistency between the two crops compared. Actual crop N status was assessed by the Nitrogen Nutrition Index (NNI), calculated as the ratio between the actual and the critical crop N contents (i.e., the minimum N content for maximum growth). There were strong relationships between each of SFR, FLAV and NBI with crop NNI, for most weekly measurements made throughout the two crops. For the three indices, coefficients of determination (R2) were mostly 0.65–0.91 in the autumn crop, and 0.71–0.99 in the spring crop. SFR values were generally comparable between the two crops, which enabled the derivation of common relationships with NNI for individual phenological phases that applied to both cropping seasons. FLAV and NBI values were not comparable between the two crops; FLAV values were appreciably higher throughout the spring crop, which was attributed to the higher solar radiation. Consequently, phenological relationships of FLAV and NBI with NNI were established for each individual cropping season. Our findings suggested that SFR was the most consistent index between cropping seasons, and that NBI was the most sensitive index within each season. Regardless of the index and crops, all fluorescence indices were weakly related to crop NNI during the short vegetative phase while stronger relationships were found in the reproductive and harvest phases. This study also showed that the three fluorescence indices were sensitive to and able to distinguish deficient from optimal crop N status, but that they were insensitive to discriminate optimal from slightly excessive N status. Overall, this study demonstrated that fluorescence indices of chlorophyll content (SFR), flavonols content (FLAV) and nitrogen sufficiency (NBI) can be used as reliable indicators of crop N status in cucumber crops; however, there was variability in FLAV and NBI values between cropping seasons and a lack of sensitivity in the range of optimal to slightly excessive crop N status.

HOW DEAD ARE DEAD GALAXIES? MID-INFRARED FLUXES OF QUIESCENT GALAXIES AT REDSHIFT 0.3 &lt;z&lt; 2.5: IMPLICATIONS FOR STAR FORMATION RATES AND DUST HEATING

We investigate the star formation rates of quiescent galaxies at high redshift (0.3 < z < 2.5) using 3D-HST WFC3 grism spectroscopy and Spitzer mid-infrared data. We select quiescent galaxies on the basis of the widely used UVJ color-color criteria. Spectral energy distribution fitting (rest frame optical and near-IR) indicates very low star formation rates for quiescent galaxies (sSFR ~ 10^-12 yr^-1). However, SED fitting can miss star formation if it is hidden behind high dust obscuration and ionizing radiation is re-emitted in the mid-infrared. It is therefore fundamental to measure the dust-obscured SFRs with a mid-IR indicator. We stack the MIPS-24um images of quiescent objects in five redshift bins centered on z = 0.5, 0.9, 1.2, 1.7, 2.2 and perform aperture photometry. Including direct 24um detections, we find sSFR ~ 10^-11.9 * (1+z)^4 yr^-1. These values are higher than those indicated by SED fitting, but at each redshift they are 20-40 times lower than those of typical star forming galaxies. The true SFRs of quiescent galaxies might be even lower, as we show that the mid-IR fluxes can be due to processes unrelated to ongoing star formation, such as cirrus dust heated by old stellar populations and circumstellar dust. Our measurements show that star formation quenching is very efficient at every redshift. The measured SFR values are at z > 1.5 marginally consistent with the ones expected from gas recycling (assuming that mass loss from evolved stars refuels star formation) and well above that at lower redshifts.

Interaction effects on galaxy pairs with Gemini/GMOS – II: oxygen abundance gradients

In this paper, we derive oxygen abundance gradients from H ii regions located in 11 galaxies in eight systems of close pairs. Long-slit spectra in the range 4400–7300 Å were obtained with the Gemini Multi-Object Spectrograph at Gemini South (GMOS-S). Spatial profiles of oxygen abundance in the gaseous phase along galaxy discs were obtained using calibrations based on strong emission lines (N2 and O3N2). We found oxygen gradients to be significantly flatter for all the studied galaxies than those in typical isolated spiral galaxies. Four objects in our sample, AM 1219A, AM 1256B, AM 2030A and AM 2030B, show a clear break in the oxygen abundance at galactocentric radius R/R25 between 0.2 and 0.5. For AM 1219A and AM 1256B, we found negative slopes for the inner gradients, and for AM 2030B, we found a positive slope. All three cases show a flatter behaviour to the outskirts of the galaxies. For AM 2030A, we found a positive slope for the outer gradient, while the inner gradient is almost compatible with a flat behaviour. We found a decrease of star formation efficiency in the zone that corresponds to the oxygen abundance gradient break for AM 1219A and AM 2030B. For the former, a minimum in the estimated metallicities was found very close to the break zone, which could be associated with a corotation radius. However, AM 1256B and AM 2030A, present a star formation rate maximum but not an extreme oxygen abundance value. All four interacting systems that show oxygen gradient breaks have extreme SFR values located very close to break zones.The H ii regions located in close pairs of galaxies follow the same relation between the ionization parameter and the oxygen abundance as those regions in isolated galaxies.

PHYSICAL PROPERTIES, STAR FORMATION, AND ACTIVE GALACTIC NUCLEUS ACTIVITY IN BALMER BREAK GALAXIES AT 0 &lt;z&lt; 1

We present a spectroscopic study with the derivation of the physical properties of 37 Balmer break galaxies, which have the necessary lines to locate them in star-forming-AGN diagnostic diagrams. These galaxies span a redshift range from 0.045 to 0.93 and are somewhat less massive than similar samples of previous works. The studied sample has multiwavelength photometric data coverage from the ultraviolet to MIR Spitzer bands. We investigate the connection between star formation and AGN activity via optical, mass-excitation (MEx) and MIR diagnostic diagrams. Through optical diagrams, 31 (84%) star-forming galaxies, 2 (5%) composite galaxies and 3 (8%) AGNs were classified, whereas from the MEx diagram only one galaxy was classified as AGN. A total of 19 galaxies have photometry available in all the IRAC/Spitzer bands. Of these, 3 AGN candidates were not classified as AGN in the optical diagrams, suggesting they are dusty/obscured AGNs, or that nuclear star formation has diluted their contributions. Furthermore, the relationship between SFR surface density (\Sigma_{SFR}) and stellar mass surface density per time unit (\Sigma_{M_{\ast}/\tau}) as a function of redshift was investigated using the [OII] \lambda3727, 3729, H\alpha \lambda6563 luminosities, which revealed that both quantities are larger for higher redshift galaxies. We also studied the SFR and SSFR versus stellar mass and color relations, with the more massive galaxies having higher SFR values but lower SSFR values than less massive galaxies. These results are consistent with previous ones showing that, at a given mass, high-redshift galaxies have on average larger SFR and SSFR values than low-redshift galaxies. Finally, bluer galaxies have larger SSFR values than redder galaxies and for a given color the SSFR is larger for higher redshift galaxies.

STAR FORMATION IN PARTIALLY GAS-DEPLETED SPIRAL GALAXIES

Broadband B and R and H-alpha images have been obtained with the 4.1-m SOAR telescope atop Cerro Pachon, Chile for 29 spiral galaxies in the Pegasus I galaxy cluster and for 18 spirals in non-cluster environments. Pegasus I is a spiral-rich cluster with a low density intracluster medium and a low galaxy velocity dispersion. When combined with neutral hydrogen (HI) data obtained with the Arecibo 305-m radiotelescope, acquired by Levy et al. (2007) and by Springob et al. (2005a), we study the star formation rates in disk galaxies as a function of their HI deficiency. To quantify HI deficiency, we use the usual logarithmic deficiency parameter, DEF. The specific star formation rate (SSFR) is quantified by the logarithmic flux ratio of H-alpha flux to R band flux, and thus roughly characterizes the logarithmic SFR per unit stellar mass. We find a clear correlation between the global SFR per unit stellar mass and DEF, such that the SFR is lower in more HI-deficient galaxies. This correlation appears to extend from the most gas-rich to the most gas-poor galaxies. We also find a correlation between the central SFR per unit mass relative to the global values, in the sense that the more HI-deficient galaxies have a higher central SFR per unit mass relative to their global SFR values than do gas-rich galaxies. In fact, approximately half of the HI-depleted galaxies have highly elevated SSFRs in their central regions, indicative of a transient evolutionary state. In addition, we find a correlation between gas-depletion and the size of the H-alpha disk (relative to the R band disk); HI-poor galaxies have truncated disks. Moreover, aside from the elevated central SSFR in many gas-poor spirals, the SSFR is otherwise lower in the H-alpha disks of gas-poor galaxies than in gas-rich spirals.

Integral field optical spectroscopy of a representative sample of ULIRGs

We investigate the two-dimensional kpc-scale structure of the extinction in a representative sample of local ULIRGs using the Halpha/Hbeta line ratio.We use optical integral field spectroscopy obtained with the INTEGRAL instrument at the William Herschel Telescope. Complementary optical and near-IR high angular resolution HST images have also been used. The extinction exhibits a very complex and patchy structure in ULIRGs on kpc scales, from basically transparent regions to others deeply embedded in dust (Av~0.0 to Av~8.0 mag). Nuclear extinction covers a broad range in Av from 0.6 to 6 mag, 69% of the nuclei having Av>2.0 mag. Extinction in the external regions is substantially lower than in the nuclei with 64% of the ULIRGs in the sample having median Av of less than 2 mag for the entire galaxy. While post-coalescence nuclei tend to cluster around Av values of 2 to 3 mag, pre-coalescence nuclei appear more homogeneously distributed over the entire 0.4 mag <Av< 7.7 mag range. For the average extinction (Av~2.0 derived for the ULIRGs of the sample, the ratio of the de-reddened to observed SFR values is 6. The extinction-corrected, Halpha-based SFR ranges from 10 to 300 Msun/yr. For only 28% of the cases the de-reddened SFR is <20 Msun/yr, whereas for the observed SFR this percentage increases to 72%. The IR-based SFR is always higher than the optical-based one, with differences ranging from about 2 to up to 30. The nuclear observed SFR has an average contribution to the total one of 16% for the entire sample. Once corrected for extinction, the average value becomes 31%. Because of mostly extinction effects, the optical (I-band) half-light radius in the sample galaxies is on average a factor 2.3 larger than the corresponding near-IR (H-band) value.

On the radio continuum, molecular gas content and optical emission of Markarian galaxies with Seyfert nuclei

In this paper we interpret C and X-band radio continuum observations of a sample of Markarian galaxies. The results are briefly discussed. Seyfert 2 galaxies show sistematically higher HI mass-to-blue magnitude than Seyfert 1 galaxies, as well as higher radio to far-infrared luminosities. The observational properties are interpreted in terms of simple non-thermal and dust emission. We obtained radio brightness temperatures, equipartion magnetic fields and total magnetic densities for the disks. Upper limits for thermal densities are derived from simple free-free emission. Star formation rates and mean supernova rates are estimated for individual Markarian galaxies. The SFR values of the most luminous Markarian galaxies are considerably higher than those found in compact blue dwarf galaxies and also in gas-rich, early-type spirals.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html